Merge pull request 'Add built-in theme support with various pre-defined themes' (#28) from theming into main

Reviewed-on: #28

Cargo.toml

@@ -9,7 +9,7 @@ members = [
 exclude = []
 
 [workspace.package]
-version = "0.1.8"
+version = "0.1.9"
 edition = "2021"
 authors = ["Owlibou"]
 license = "AGPL-3.0"

PKGBUILD

@@ -1,6 +1,6 @@
 # Maintainer: vikingowl <christian@nachtigall.dev>
 pkgname=owlen
-pkgver=0.1.8
+pkgver=0.1.9
 pkgrel=1
 pkgdesc="Terminal User Interface LLM client for Ollama with chat and code assistance features"
 arch=('x86_64')
@@ -40,5 +40,11 @@ package() {
 
     # Install documentation
     install -Dm644 README.md "$pkgdir/usr/share/doc/$pkgname/README.md"
+
+    # Install built-in themes for reference
+    install -Dm644 themes/README.md "$pkgdir/usr/share/$pkgname/themes/README.md"
+    for theme in themes/*.toml; do
+        install -Dm644 "$theme" "$pkgdir/usr/share/$pkgname/themes/$(basename $theme)"
+    done
 }
 

README.md

@@ -3,13 +3,13 @@
 > Terminal-native assistant for running local language models with a comfortable TUI.
 
 ![Status](https://img.shields.io/badge/status-alpha-yellow)
-![Version](https://img.shields.io/badge/version-0.1.8-blue)
+![Version](https://img.shields.io/badge/version-0.1.9-blue)
 ![Rust](https://img.shields.io/badge/made_with-Rust-ffc832?logo=rust&logoColor=white)
 ![License](https://img.shields.io/badge/license-AGPL--3.0-blue)
 
 ## Alpha Status
 
-- This project is currently in **alpha** (v0.1.8) and under active development.
+- This project is currently in **alpha** (v0.1.9) and under active development.
 - Core features are functional but expect occasional bugs and missing polish.
 - Breaking changes may occur between releases as we refine the API.
 - Feedback, bug reports, and contributions are very welcome!
@@ -48,6 +48,7 @@ The OWLEN interface features a clean, multi-panel layout with vim-inspired navig
 - **Session Management** - Start new conversations, clear history, browse saved sessions
 - **Thinking Mode Support** - Dedicated panel for extended reasoning content
 - **Bracketed Paste** - Safe paste handling for multi-line content
+- **Theming System** - 10 built-in themes plus custom theme support
 
 ### Code Client (`owlen-code`) [Experimental]
 - All chat client features
@@ -140,14 +141,17 @@ cargo build --release --bin owlen-code --features code-client
 - `Enter` - Send message and return to normal mode
 - `Ctrl-J` / `Shift-Enter` - Insert newline
 - `Ctrl-↑/↓` - Navigate input history
+- `Ctrl-A` / `Ctrl-E` - Jump to start/end of line
+- `Ctrl-W` / `Ctrl-B` - Word movement
+- `Ctrl-R` - Redo
 - Paste events handled automatically
 
 **Visual Mode**:
 - `j/k/h/l` - Extend selection
 - `w/b/e` - Word-based selection
 - `y` - Yank (copy) selection
-- `d` - Cut selection (Input panel only)
+- `d` / `Delete` - Cut selection (Input panel only)
-- `Esc` - Cancel selection
+- `Esc` / `v` - Cancel selection
 
 **Command Mode**:
 - `Tab` - Autocomplete selected command suggestion
@@ -160,8 +164,17 @@ cargo build --release --bin owlen-code --features code-client
 - `:save [name]` / `:w [name]` - Save current conversation
 - `:load` / `:open` - Browse and load saved sessions
 - `:sessions` / `:ls` - List saved sessions
+- `:theme <name>` - Switch theme (saved to config)
+- `:themes` - Browse themes in interactive modal
+- `:reload` - Reload configuration and themes
 - *Commands show real-time suggestions as you type*
 
+**Theme Browser** (accessed via `:themes`):
+- `j` / `k` / `↑` / `↓` - Navigate themes
+- `Enter` - Apply selected theme
+- `g` / `G` - Jump to top/bottom
+- `Esc` / `q` - Close browser
+
 **Session Browser** (accessed via `:load` or `:sessions`):
 - `j` / `k` / `↑` / `↓` - Navigate sessions
 - `Enter` - Load selected session
@@ -210,15 +223,63 @@ generate_descriptions = true  # AI-generated summaries for saved sessions
 
 Configuration is automatically saved when you change models or providers.
 
+### Theming
+
+OWLEN includes 10 built-in themes that are embedded in the binary. You can also create custom themes.
+
+**Built-in themes:**
+- `default_dark` (default) - High-contrast dark theme
+- `default_light` - Clean light theme
+- `gruvbox` - Retro warm color scheme
+- `dracula` - Vibrant purple and cyan
+- `solarized` - Precision colors for readability
+- `midnight-ocean` - Deep blue oceanic theme
+- `rose-pine` - Soho vibes with muted pastels
+- `monokai` - Classic code editor theme
+- `material-dark` - Google's Material Design dark variant
+- `material-light` - Google's Material Design light variant
+
+**Commands:**
+- `:theme <name>` - Switch theme instantly (automatically saved to config)
+- `:themes` - Browse and select themes in an interactive modal
+- `:reload` - Reload configuration and themes
+
+**Setting default theme:**
+```toml
+[ui]
+theme = "gruvbox"  # or any built-in/custom theme name
+```
+
+**Creating custom themes:**
+
+Create a `.toml` file in `~/.config/owlen/themes/`:
+
+```toml
+# ~/.config/owlen/themes/my-theme.toml
+name = "my-theme"
+text = "#ffffff"
+background = "#000000"
+focused_panel_border = "#ff00ff"
+unfocused_panel_border = "#800080"
+user_message_role = "#00ffff"
+assistant_message_role = "#ffff00"
+# ... see themes/README.md for full schema
+```
+
+**Colors** can be hex RGB (`#rrggbb`) or named colors (`red`, `blue`, `lightgreen`, etc.). See `themes/README.md` for the complete list of supported color names.
+
+For reference theme files and detailed documentation, see the `themes/` directory in the repository or `/usr/share/owlen/themes/` after installation.
+
 ## Repository Layout
 
 ```
 owlen/
 ├── crates/
-│   ├── owlen-core/       # Core types, session management, shared UI components
+│   ├── owlen-core/       # Core types, session management, theming, shared UI components
 │   ├── owlen-ollama/     # Ollama provider implementation
 │   ├── owlen-tui/        # TUI components (chat_app, code_app, rendering)
 │   └── owlen-cli/        # Binary entry points (owlen, owlen-code)
+├── themes/               # Built-in theme definitions (embedded in binary)
 ├── LICENSE               # AGPL-3.0 License
 ├── Cargo.toml            # Workspace configuration
 └── README.md
@@ -270,9 +331,9 @@ cargo fmt
 - [x] Bracketed paste support
 - [x] Command autocompletion with Tab completion
 - [x] Session persistence (save/load conversations)
+- [x] Theming system with 9 built-in themes and custom theme support
 
 ### In Progress
-- [ ] Theming options and color customization
 - [ ] Enhanced configuration UX (in-app settings)
 - [ ] Conversation export (Markdown, JSON, plain text)
 
@@ -322,4 +383,4 @@ Built with:
 
 ---
 
-**Status**: Alpha v0.1.8 | **License**: AGPL-3.0 | **Made with Rust** 🦀
+**Status**: Alpha v0.1.9 | **License**: AGPL-3.0 | **Made with Rust** 🦀

crates/owlen-core/Cargo.toml

@@ -24,6 +24,7 @@ async-trait = "0.1.73"
 toml = "0.8.0"
 shellexpand = "3.1.0"
 dirs = "5.0"
+ratatui = { workspace = true }
 
 [dev-dependencies]
 tokio-test = { workspace = true }

crates/owlen-core/src/config.rs

@@ -202,7 +202,7 @@ pub struct UiSettings {
 
 impl UiSettings {
     fn default_theme() -> String {
-        "default".to_string()
+        "default_dark".to_string()
     }
 
     fn default_word_wrap() -> bool {
@@ -388,7 +388,9 @@ mod tests {
         #[cfg(target_os = "macos")]
         {
             // macOS should use ~/Library/Application Support
-            assert!(path.to_string_lossy().contains("Library/Application Support"));
+            assert!(path
+                .to_string_lossy()
+                .contains("Library/Application Support"));
         }
 
         println!("Config conversation path: {}", path.display());

crates/owlen-core/src/conversation.rs

@@ -277,20 +277,26 @@ impl ConversationManager {
         &self,
         storage: &StorageManager,
         name: Option<String>,
-        description: Option<String>
+        description: Option<String>,
     ) -> Result<PathBuf> {
         storage.save_conversation_with_description(&self.active, name, description)
     }
 
     /// Load a conversation from disk and make it active
-    pub fn load_from_disk(&mut self, storage: &StorageManager, path: impl AsRef<Path>) -> Result<()> {
+    pub fn load_from_disk(
+        &mut self,
+        storage: &StorageManager,
+        path: impl AsRef<Path>,
+    ) -> Result<()> {
         let conversation = storage.load_conversation(path)?;
         self.load(conversation);
         Ok(())
     }
 
     /// List all saved sessions
-    pub fn list_saved_sessions(storage: &StorageManager) -> Result<Vec<crate::storage::SessionMeta>> {
+    pub fn list_saved_sessions(
+        storage: &StorageManager,
+    ) -> Result<Vec<crate::storage::SessionMeta>> {
         storage.list_sessions()
     }
 }

crates/owlen-core/src/lib.rs

@@ -12,6 +12,7 @@ pub mod provider;
 pub mod router;
 pub mod session;
 pub mod storage;
+pub mod theme;
 pub mod types;
 pub mod ui;
 pub mod wrap_cursor;
@@ -24,6 +25,7 @@ pub use model::*;
 pub use provider::*;
 pub use router::*;
 pub use session::*;
+pub use theme::*;
 
 /// Result type used throughout the OWLEN ecosystem
 pub type Result<T> = std::result::Result<T, Error>;

crates/owlen-core/src/session.rs

@@ -231,7 +231,15 @@ impl SessionController {
         if conv.messages.len() == 1 {
             let first_msg = &conv.messages[0];
             let preview = first_msg.content.chars().take(50).collect::<String>();
-            return Ok(format!("{}{}", preview, if first_msg.content.len() > 50 { "..." } else { "" }));
+            return Ok(format!(
+                "{}{}",
+                preview,
+                if first_msg.content.len() > 50 {
+                    "..."
+                } else {
+                    ""
+                }
+            ));
         }
 
         // Build a summary prompt from the first few and last few messages
@@ -240,7 +248,8 @@ impl SessionController {
         // Add system message to guide the description
         summary_messages.push(crate::types::Message::system(
             "Summarize this conversation in 1-2 short sentences (max 100 characters). \
-             Focus on the main topic or question being discussed. Be concise and descriptive.".to_string()
+             Focus on the main topic or question being discussed. Be concise and descriptive."
+                .to_string(),
         ));
 
         // Include first message
@@ -283,7 +292,15 @@ impl SessionController {
                 if description.is_empty() {
                     let first_msg = &conv.messages[0];
                     let preview = first_msg.content.chars().take(50).collect::<String>();
-                    return Ok(format!("{}{}", preview, if first_msg.content.len() > 50 { "..." } else { "" }));
+                    return Ok(format!(
+                        "{}{}",
+                        preview,
+                        if first_msg.content.len() > 50 {
+                            "..."
+                        } else {
+                            ""
+                        }
+                    ));
                 }
 
                 // Truncate if too long
@@ -298,7 +315,15 @@ impl SessionController {
                 // Fallback to simple description if AI generation fails
                 let first_msg = &conv.messages[0];
                 let preview = first_msg.content.chars().take(50).collect::<String>();
-                Ok(format!("{}{}", preview, if first_msg.content.len() > 50 { "..." } else { "" }))
+                Ok(format!(
+                    "{}{}",
+                    preview,
+                    if first_msg.content.len() > 50 {
+                        "..."
+                    } else {
+                        ""
+                    }
+                ))
             }
         }
     }

crates/owlen-core/src/storage.rs

@@ -45,10 +45,7 @@ impl StorageManager {
         // Ensure the directory exists
         if !sessions_dir.exists() {
             fs::create_dir_all(&sessions_dir).map_err(|e| {
-                Error::Storage(format!(
+                Error::Storage(format!("Failed to create sessions directory: {}", e))
-                    "Failed to create sessions directory: {}",
-                    e
-                ))
             })?;
         }
 
@@ -66,7 +63,11 @@ impl StorageManager {
     }
 
     /// Save a conversation to disk
-    pub fn save_conversation(&self, conversation: &Conversation, name: Option<String>) -> Result<PathBuf> {
+    pub fn save_conversation(
+        &self,
+        conversation: &Conversation,
+        name: Option<String>,
+    ) -> Result<PathBuf> {
         self.save_conversation_with_description(conversation, name, None)
     }
 
@@ -75,7 +76,7 @@ impl StorageManager {
         &self,
         conversation: &Conversation,
         name: Option<String>,
-        description: Option<String>
+        description: Option<String>,
     ) -> Result<PathBuf> {
         let filename = if let Some(ref session_name) = name {
             // Use provided name, sanitized
@@ -101,26 +102,22 @@ impl StorageManager {
             save_conv.description = description;
         }
 
-        let json = serde_json::to_string_pretty(&save_conv).map_err(|e| {
+        let json = serde_json::to_string_pretty(&save_conv)
-            Error::Storage(format!("Failed to serialize conversation: {}", e))
+            .map_err(|e| Error::Storage(format!("Failed to serialize conversation: {}", e)))?;
-        })?;
 
-        fs::write(&path, json).map_err(|e| {
+        fs::write(&path, json)
-            Error::Storage(format!("Failed to write session file: {}", e))
+            .map_err(|e| Error::Storage(format!("Failed to write session file: {}", e)))?;
-        })?;
 
         Ok(path)
     }
 
     /// Load a conversation from disk
     pub fn load_conversation(&self, path: impl AsRef<Path>) -> Result<Conversation> {
-        let content = fs::read_to_string(path.as_ref()).map_err(|e| {
+        let content = fs::read_to_string(path.as_ref())
-            Error::Storage(format!("Failed to read session file: {}", e))
+            .map_err(|e| Error::Storage(format!("Failed to read session file: {}", e)))?;
-        })?;
 
-        let conversation: Conversation = serde_json::from_str(&content).map_err(|e| {
+        let conversation: Conversation = serde_json::from_str(&content)
-            Error::Storage(format!("Failed to parse session file: {}", e))
+            .map_err(|e| Error::Storage(format!("Failed to parse session file: {}", e)))?;
-        })?;
 
         Ok(conversation)
     }
@@ -129,14 +126,12 @@ impl StorageManager {
     pub fn list_sessions(&self) -> Result<Vec<SessionMeta>> {
         let mut sessions = Vec::new();
 
-        let entries = fs::read_dir(&self.sessions_dir).map_err(|e| {
+        let entries = fs::read_dir(&self.sessions_dir)
-            Error::Storage(format!("Failed to read sessions directory: {}", e))
+            .map_err(|e| Error::Storage(format!("Failed to read sessions directory: {}", e)))?;
-        })?;
 
         for entry in entries {
-            let entry = entry.map_err(|e| {
+            let entry = entry
-                Error::Storage(format!("Failed to read directory entry: {}", e))
+                .map_err(|e| Error::Storage(format!("Failed to read directory entry: {}", e)))?;
-            })?;
 
             let path = entry.path();
             if path.extension().and_then(|s| s.to_str()) != Some("json") {
@@ -172,9 +167,8 @@ impl StorageManager {
 
     /// Delete a saved session
     pub fn delete_session(&self, path: impl AsRef<Path>) -> Result<()> {
-        fs::remove_file(path.as_ref()).map_err(|e| {
+        fs::remove_file(path.as_ref())
-            Error::Storage(format!("Failed to delete session file: {}", e))
+            .map_err(|e| Error::Storage(format!("Failed to delete session file: {}", e)))
-        })
     }
 
     /// Get the sessions directory path
@@ -237,7 +231,9 @@ mod tests {
         #[cfg(target_os = "macos")]
         {
             // macOS should use ~/Library/Application Support
-            assert!(path.to_string_lossy().contains("Library/Application Support"));
+            assert!(path
+                .to_string_lossy()
+                .contains("Library/Application Support"));
         }
 
         println!("Default sessions directory: {}", path.display());
@@ -257,10 +253,13 @@ mod tests {
 
         let mut conv = Conversation::new("test-model".to_string());
         conv.messages.push(Message::user("Hello".to_string()));
-        conv.messages.push(Message::assistant("Hi there!".to_string()));
+        conv.messages
+            .push(Message::assistant("Hi there!".to_string()));
 
         // Save conversation
-        let path = storage.save_conversation(&conv, Some("test_session".to_string())).unwrap();
+        let path = storage
+            .save_conversation(&conv, Some("test_session".to_string()))
+            .unwrap();
         assert!(path.exists());
 
         // Load conversation
@@ -280,7 +279,9 @@ mod tests {
         for i in 0..3 {
             let mut conv = Conversation::new("test-model".to_string());
             conv.messages.push(Message::user(format!("Message {}", i)));
-            storage.save_conversation(&conv, Some(format!("session_{}", i))).unwrap();
+            storage
+                .save_conversation(&conv, Some(format!("session_{}", i)))
+                .unwrap();
         }
 
         // List sessions

crates/owlen-core/src/theme.rs

@@ -0,0 +1,645 @@
+//! Theming system for OWLEN TUI
+//!
+//! Provides customizable color schemes for all UI components.
+
+use ratatui::style::Color;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+/// A complete theme definition for OWLEN TUI
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Theme {
+    /// Name of the theme
+    pub name: String,
+
+    /// Default text color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub text: Color,
+
+    /// Default background color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub background: Color,
+
+    /// Border color for focused panels
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub focused_panel_border: Color,
+
+    /// Border color for unfocused panels
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub unfocused_panel_border: Color,
+
+    /// Color for user message role indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub user_message_role: Color,
+
+    /// Color for assistant message role indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub assistant_message_role: Color,
+
+    /// Color for thinking panel title
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub thinking_panel_title: Color,
+
+    /// Background color for command bar
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub command_bar_background: Color,
+
+    /// Status line background color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub status_background: Color,
+
+    /// Color for Normal mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_normal: Color,
+
+    /// Color for Editing mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_editing: Color,
+
+    /// Color for Model Selection mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_model_selection: Color,
+
+    /// Color for Provider Selection mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_provider_selection: Color,
+
+    /// Color for Help mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_help: Color,
+
+    /// Color for Visual mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_visual: Color,
+
+    /// Color for Command mode indicator
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub mode_command: Color,
+
+    /// Selection/highlight background color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub selection_bg: Color,
+
+    /// Selection/highlight foreground color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub selection_fg: Color,
+
+    /// Cursor indicator color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub cursor: Color,
+
+    /// Placeholder text color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub placeholder: Color,
+
+    /// Warning/error message color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub error: Color,
+
+    /// Success/info message color
+    #[serde(deserialize_with = "deserialize_color")]
+    #[serde(serialize_with = "serialize_color")]
+    pub info: Color,
+}
+
+impl Default for Theme {
+    fn default() -> Self {
+        default_dark()
+    }
+}
+
+/// Get the default themes directory path
+pub fn default_themes_dir() -> PathBuf {
+    let config_dir = PathBuf::from(shellexpand::tilde(crate::config::DEFAULT_CONFIG_PATH).as_ref())
+        .parent()
+        .map(|p| p.to_path_buf())
+        .unwrap_or_else(|| PathBuf::from("~/.config/owlen"));
+
+    config_dir.join("themes")
+}
+
+/// Load all available themes (built-in + custom)
+pub fn load_all_themes() -> HashMap<String, Theme> {
+    let mut themes = HashMap::new();
+
+    // Load built-in themes
+    for (name, theme) in built_in_themes() {
+        themes.insert(name, theme);
+    }
+
+    // Load custom themes from disk
+    let themes_dir = default_themes_dir();
+    if let Ok(entries) = fs::read_dir(&themes_dir) {
+        for entry in entries.flatten() {
+            let path = entry.path();
+            if path.extension().and_then(|s| s.to_str()) == Some("toml") {
+                let name = path
+                    .file_stem()
+                    .and_then(|s| s.to_str())
+                    .unwrap_or("unknown")
+                    .to_string();
+
+                match load_theme_from_file(&path) {
+                    Ok(theme) => {
+                        themes.insert(name.clone(), theme);
+                    }
+                    Err(e) => {
+                        eprintln!("Warning: Failed to load custom theme '{}': {}", name, e);
+                    }
+                }
+            }
+        }
+    }
+
+    themes
+}
+
+/// Load a theme from a TOML file
+pub fn load_theme_from_file(path: &Path) -> Result<Theme, String> {
+    let content =
+        fs::read_to_string(path).map_err(|e| format!("Failed to read theme file: {}", e))?;
+
+    toml::from_str(&content).map_err(|e| format!("Failed to parse theme file: {}", e))
+}
+
+/// Get a theme by name (built-in or custom)
+pub fn get_theme(name: &str) -> Option<Theme> {
+    load_all_themes().get(name).cloned()
+}
+
+/// Get all built-in themes (embedded in the binary)
+pub fn built_in_themes() -> HashMap<String, Theme> {
+    let mut themes = HashMap::new();
+
+    // Load embedded theme files
+    let embedded_themes = [
+        (
+            "default_dark",
+            include_str!("../../../themes/default_dark.toml"),
+        ),
+        (
+            "default_light",
+            include_str!("../../../themes/default_light.toml"),
+        ),
+        ("gruvbox", include_str!("../../../themes/gruvbox.toml")),
+        ("dracula", include_str!("../../../themes/dracula.toml")),
+        ("solarized", include_str!("../../../themes/solarized.toml")),
+        (
+            "midnight-ocean",
+            include_str!("../../../themes/midnight-ocean.toml"),
+        ),
+        ("rose-pine", include_str!("../../../themes/rose-pine.toml")),
+        ("monokai", include_str!("../../../themes/monokai.toml")),
+        (
+            "material-dark",
+            include_str!("../../../themes/material-dark.toml"),
+        ),
+        (
+            "material-light",
+            include_str!("../../../themes/material-light.toml"),
+        ),
+    ];
+
+    for (name, content) in embedded_themes {
+        match toml::from_str::<Theme>(content) {
+            Ok(theme) => {
+                themes.insert(name.to_string(), theme);
+            }
+            Err(e) => {
+                eprintln!("Warning: Failed to parse built-in theme '{}': {}", name, e);
+                // Fallback to hardcoded version if parsing fails
+                if let Some(fallback) = get_fallback_theme(name) {
+                    themes.insert(name.to_string(), fallback);
+                }
+            }
+        }
+    }
+
+    themes
+}
+
+/// Get fallback hardcoded theme (used if embedded TOML fails to parse)
+fn get_fallback_theme(name: &str) -> Option<Theme> {
+    match name {
+        "default_dark" => Some(default_dark()),
+        "default_light" => Some(default_light()),
+        "gruvbox" => Some(gruvbox()),
+        "dracula" => Some(dracula()),
+        "solarized" => Some(solarized()),
+        "midnight-ocean" => Some(midnight_ocean()),
+        "rose-pine" => Some(rose_pine()),
+        "monokai" => Some(monokai()),
+        "material-dark" => Some(material_dark()),
+        "material-light" => Some(material_light()),
+        _ => None,
+    }
+}
+
+/// Default dark theme
+fn default_dark() -> Theme {
+    Theme {
+        name: "default_dark".to_string(),
+        text: Color::White,
+        background: Color::Black,
+        focused_panel_border: Color::LightMagenta,
+        unfocused_panel_border: Color::Rgb(95, 20, 135),
+        user_message_role: Color::LightBlue,
+        assistant_message_role: Color::Yellow,
+        thinking_panel_title: Color::LightMagenta,
+        command_bar_background: Color::Black,
+        status_background: Color::Black,
+        mode_normal: Color::LightBlue,
+        mode_editing: Color::LightGreen,
+        mode_model_selection: Color::LightYellow,
+        mode_provider_selection: Color::LightCyan,
+        mode_help: Color::LightMagenta,
+        mode_visual: Color::Magenta,
+        mode_command: Color::Yellow,
+        selection_bg: Color::LightBlue,
+        selection_fg: Color::Black,
+        cursor: Color::Magenta,
+        placeholder: Color::DarkGray,
+        error: Color::Red,
+        info: Color::LightGreen,
+    }
+}
+
+/// Default light theme
+fn default_light() -> Theme {
+    Theme {
+        name: "default_light".to_string(),
+        text: Color::Black,
+        background: Color::White,
+        focused_panel_border: Color::Rgb(74, 144, 226),
+        unfocused_panel_border: Color::Rgb(221, 221, 221),
+        user_message_role: Color::Rgb(0, 85, 164),
+        assistant_message_role: Color::Rgb(142, 68, 173),
+        thinking_panel_title: Color::Rgb(142, 68, 173),
+        command_bar_background: Color::White,
+        status_background: Color::White,
+        mode_normal: Color::Rgb(0, 85, 164),
+        mode_editing: Color::Rgb(46, 139, 87),
+        mode_model_selection: Color::Rgb(181, 137, 0),
+        mode_provider_selection: Color::Rgb(0, 139, 139),
+        mode_help: Color::Rgb(142, 68, 173),
+        mode_visual: Color::Rgb(142, 68, 173),
+        mode_command: Color::Rgb(181, 137, 0),
+        selection_bg: Color::Rgb(164, 200, 240),
+        selection_fg: Color::Black,
+        cursor: Color::Rgb(217, 95, 2),
+        placeholder: Color::Gray,
+        error: Color::Rgb(192, 57, 43),
+        info: Color::Green,
+    }
+}
+
+/// Gruvbox theme
+fn gruvbox() -> Theme {
+    Theme {
+        name: "gruvbox".to_string(),
+        text: Color::Rgb(235, 219, 178),                   // #ebdbb2
+        background: Color::Rgb(40, 40, 40),                // #282828
+        focused_panel_border: Color::Rgb(254, 128, 25),    // #fe8019 (orange)
+        unfocused_panel_border: Color::Rgb(124, 111, 100), // #7c6f64
+        user_message_role: Color::Rgb(184, 187, 38),       // #b8bb26 (green)
+        assistant_message_role: Color::Rgb(131, 165, 152), // #83a598 (blue)
+        thinking_panel_title: Color::Rgb(211, 134, 155),   // #d3869b (purple)
+        command_bar_background: Color::Rgb(60, 56, 54),    // #3c3836
+        status_background: Color::Rgb(60, 56, 54),
+        mode_normal: Color::Rgb(131, 165, 152),         // blue
+        mode_editing: Color::Rgb(184, 187, 38),         // green
+        mode_model_selection: Color::Rgb(250, 189, 47), // yellow
+        mode_provider_selection: Color::Rgb(142, 192, 124), // aqua
+        mode_help: Color::Rgb(211, 134, 155),           // purple
+        mode_visual: Color::Rgb(254, 128, 25),          // orange
+        mode_command: Color::Rgb(250, 189, 47),         // yellow
+        selection_bg: Color::Rgb(80, 73, 69),
+        selection_fg: Color::Rgb(235, 219, 178),
+        cursor: Color::Rgb(254, 128, 25),
+        placeholder: Color::Rgb(102, 92, 84),
+        error: Color::Rgb(251, 73, 52), // #fb4934
+        info: Color::Rgb(184, 187, 38),
+    }
+}
+
+/// Dracula theme
+fn dracula() -> Theme {
+    Theme {
+        name: "dracula".to_string(),
+        text: Color::Rgb(248, 248, 242),                   // #f8f8f2
+        background: Color::Rgb(40, 42, 54),                // #282a36
+        focused_panel_border: Color::Rgb(255, 121, 198),   // #ff79c6 (pink)
+        unfocused_panel_border: Color::Rgb(68, 71, 90),    // #44475a
+        user_message_role: Color::Rgb(139, 233, 253),      // #8be9fd (cyan)
+        assistant_message_role: Color::Rgb(255, 121, 198), // #ff79c6 (pink)
+        thinking_panel_title: Color::Rgb(189, 147, 249),   // #bd93f9 (purple)
+        command_bar_background: Color::Rgb(68, 71, 90),
+        status_background: Color::Rgb(68, 71, 90),
+        mode_normal: Color::Rgb(139, 233, 253),
+        mode_editing: Color::Rgb(80, 250, 123), // #50fa7b (green)
+        mode_model_selection: Color::Rgb(241, 250, 140), // #f1fa8c (yellow)
+        mode_provider_selection: Color::Rgb(139, 233, 253),
+        mode_help: Color::Rgb(189, 147, 249),
+        mode_visual: Color::Rgb(255, 121, 198),
+        mode_command: Color::Rgb(241, 250, 140),
+        selection_bg: Color::Rgb(68, 71, 90),
+        selection_fg: Color::Rgb(248, 248, 242),
+        cursor: Color::Rgb(255, 121, 198),
+        placeholder: Color::Rgb(98, 114, 164),
+        error: Color::Rgb(255, 85, 85), // #ff5555
+        info: Color::Rgb(80, 250, 123),
+    }
+}
+
+/// Solarized Dark theme
+fn solarized() -> Theme {
+    Theme {
+        name: "solarized".to_string(),
+        text: Color::Rgb(131, 148, 150),   // #839496 (base0)
+        background: Color::Rgb(0, 43, 54), // #002b36 (base03)
+        focused_panel_border: Color::Rgb(38, 139, 210), // #268bd2 (blue)
+        unfocused_panel_border: Color::Rgb(7, 54, 66), // #073642 (base02)
+        user_message_role: Color::Rgb(42, 161, 152), // #2aa198 (cyan)
+        assistant_message_role: Color::Rgb(203, 75, 22), // #cb4b16 (orange)
+        thinking_panel_title: Color::Rgb(108, 113, 196), // #6c71c4 (violet)
+        command_bar_background: Color::Rgb(7, 54, 66),
+        status_background: Color::Rgb(7, 54, 66),
+        mode_normal: Color::Rgb(38, 139, 210),         // blue
+        mode_editing: Color::Rgb(133, 153, 0),         // #859900 (green)
+        mode_model_selection: Color::Rgb(181, 137, 0), // #b58900 (yellow)
+        mode_provider_selection: Color::Rgb(42, 161, 152), // cyan
+        mode_help: Color::Rgb(108, 113, 196),          // violet
+        mode_visual: Color::Rgb(211, 54, 130),         // #d33682 (magenta)
+        mode_command: Color::Rgb(181, 137, 0),         // yellow
+        selection_bg: Color::Rgb(7, 54, 66),
+        selection_fg: Color::Rgb(147, 161, 161),
+        cursor: Color::Rgb(211, 54, 130),
+        placeholder: Color::Rgb(88, 110, 117),
+        error: Color::Rgb(220, 50, 47), // #dc322f (red)
+        info: Color::Rgb(133, 153, 0),
+    }
+}
+
+/// Midnight Ocean theme
+fn midnight_ocean() -> Theme {
+    Theme {
+        name: "midnight-ocean".to_string(),
+        text: Color::Rgb(192, 202, 245),
+        background: Color::Rgb(13, 17, 23),
+        focused_panel_border: Color::Rgb(88, 166, 255),
+        unfocused_panel_border: Color::Rgb(48, 54, 61),
+        user_message_role: Color::Rgb(121, 192, 255),
+        assistant_message_role: Color::Rgb(137, 221, 255),
+        thinking_panel_title: Color::Rgb(158, 206, 106),
+        command_bar_background: Color::Rgb(22, 27, 34),
+        status_background: Color::Rgb(22, 27, 34),
+        mode_normal: Color::Rgb(121, 192, 255),
+        mode_editing: Color::Rgb(158, 206, 106),
+        mode_model_selection: Color::Rgb(255, 212, 59),
+        mode_provider_selection: Color::Rgb(137, 221, 255),
+        mode_help: Color::Rgb(255, 115, 157),
+        mode_visual: Color::Rgb(246, 140, 245),
+        mode_command: Color::Rgb(255, 212, 59),
+        selection_bg: Color::Rgb(56, 139, 253),
+        selection_fg: Color::Rgb(13, 17, 23),
+        cursor: Color::Rgb(246, 140, 245),
+        placeholder: Color::Rgb(110, 118, 129),
+        error: Color::Rgb(248, 81, 73),
+        info: Color::Rgb(158, 206, 106),
+    }
+}
+
+/// Rose Pine theme
+fn rose_pine() -> Theme {
+    Theme {
+        name: "rose-pine".to_string(),
+        text: Color::Rgb(224, 222, 244),                   // #e0def4
+        background: Color::Rgb(25, 23, 36),                // #191724
+        focused_panel_border: Color::Rgb(235, 111, 146),   // #eb6f92 (love)
+        unfocused_panel_border: Color::Rgb(38, 35, 58),    // #26233a
+        user_message_role: Color::Rgb(49, 116, 143),       // #31748f (foam)
+        assistant_message_role: Color::Rgb(156, 207, 216), // #9ccfd8 (foam light)
+        thinking_panel_title: Color::Rgb(196, 167, 231),   // #c4a7e7 (iris)
+        command_bar_background: Color::Rgb(38, 35, 58),
+        status_background: Color::Rgb(38, 35, 58),
+        mode_normal: Color::Rgb(156, 207, 216),
+        mode_editing: Color::Rgb(235, 188, 186), // #ebbcba (rose)
+        mode_model_selection: Color::Rgb(246, 193, 119),
+        mode_provider_selection: Color::Rgb(49, 116, 143),
+        mode_help: Color::Rgb(196, 167, 231),
+        mode_visual: Color::Rgb(235, 111, 146),
+        mode_command: Color::Rgb(246, 193, 119),
+        selection_bg: Color::Rgb(64, 61, 82),
+        selection_fg: Color::Rgb(224, 222, 244),
+        cursor: Color::Rgb(235, 111, 146),
+        placeholder: Color::Rgb(110, 106, 134),
+        error: Color::Rgb(235, 111, 146),
+        info: Color::Rgb(156, 207, 216),
+    }
+}
+
+/// Monokai theme
+fn monokai() -> Theme {
+    Theme {
+        name: "monokai".to_string(),
+        text: Color::Rgb(248, 248, 242),                   // #f8f8f2
+        background: Color::Rgb(39, 40, 34),                // #272822
+        focused_panel_border: Color::Rgb(249, 38, 114),    // #f92672 (pink)
+        unfocused_panel_border: Color::Rgb(117, 113, 94),  // #75715e
+        user_message_role: Color::Rgb(102, 217, 239),      // #66d9ef (cyan)
+        assistant_message_role: Color::Rgb(174, 129, 255), // #ae81ff (purple)
+        thinking_panel_title: Color::Rgb(230, 219, 116),   // #e6db74 (yellow)
+        command_bar_background: Color::Rgb(39, 40, 34),
+        status_background: Color::Rgb(39, 40, 34),
+        mode_normal: Color::Rgb(102, 217, 239),
+        mode_editing: Color::Rgb(166, 226, 46), // #a6e22e (green)
+        mode_model_selection: Color::Rgb(230, 219, 116),
+        mode_provider_selection: Color::Rgb(102, 217, 239),
+        mode_help: Color::Rgb(174, 129, 255),
+        mode_visual: Color::Rgb(249, 38, 114),
+        mode_command: Color::Rgb(230, 219, 116),
+        selection_bg: Color::Rgb(117, 113, 94),
+        selection_fg: Color::Rgb(248, 248, 242),
+        cursor: Color::Rgb(249, 38, 114),
+        placeholder: Color::Rgb(117, 113, 94),
+        error: Color::Rgb(249, 38, 114),
+        info: Color::Rgb(166, 226, 46),
+    }
+}
+
+/// Material Dark theme
+fn material_dark() -> Theme {
+    Theme {
+        name: "material-dark".to_string(),
+        text: Color::Rgb(238, 255, 255),                   // #eeffff
+        background: Color::Rgb(38, 50, 56),                // #263238
+        focused_panel_border: Color::Rgb(128, 203, 196),   // #80cbc4 (cyan)
+        unfocused_panel_border: Color::Rgb(84, 110, 122),  // #546e7a
+        user_message_role: Color::Rgb(130, 170, 255),      // #82aaff (blue)
+        assistant_message_role: Color::Rgb(199, 146, 234), // #c792ea (purple)
+        thinking_panel_title: Color::Rgb(255, 203, 107),   // #ffcb6b (yellow)
+        command_bar_background: Color::Rgb(33, 43, 48),
+        status_background: Color::Rgb(33, 43, 48),
+        mode_normal: Color::Rgb(130, 170, 255),
+        mode_editing: Color::Rgb(195, 232, 141), // #c3e88d (green)
+        mode_model_selection: Color::Rgb(255, 203, 107),
+        mode_provider_selection: Color::Rgb(128, 203, 196),
+        mode_help: Color::Rgb(199, 146, 234),
+        mode_visual: Color::Rgb(240, 113, 120), // #f07178 (red)
+        mode_command: Color::Rgb(255, 203, 107),
+        selection_bg: Color::Rgb(84, 110, 122),
+        selection_fg: Color::Rgb(238, 255, 255),
+        cursor: Color::Rgb(255, 204, 0),
+        placeholder: Color::Rgb(84, 110, 122),
+        error: Color::Rgb(240, 113, 120),
+        info: Color::Rgb(195, 232, 141),
+    }
+}
+
+/// Material Light theme
+fn material_light() -> Theme {
+    Theme {
+        name: "material-light".to_string(),
+        text: Color::Rgb(33, 33, 33),
+        background: Color::Rgb(236, 239, 241),
+        focused_panel_border: Color::Rgb(0, 150, 136),
+        unfocused_panel_border: Color::Rgb(176, 190, 197),
+        user_message_role: Color::Rgb(68, 138, 255),
+        assistant_message_role: Color::Rgb(124, 77, 255),
+        thinking_panel_title: Color::Rgb(245, 124, 0),
+        command_bar_background: Color::Rgb(255, 255, 255),
+        status_background: Color::Rgb(255, 255, 255),
+        mode_normal: Color::Rgb(68, 138, 255),
+        mode_editing: Color::Rgb(56, 142, 60),
+        mode_model_selection: Color::Rgb(245, 124, 0),
+        mode_provider_selection: Color::Rgb(0, 150, 136),
+        mode_help: Color::Rgb(124, 77, 255),
+        mode_visual: Color::Rgb(211, 47, 47),
+        mode_command: Color::Rgb(245, 124, 0),
+        selection_bg: Color::Rgb(176, 190, 197),
+        selection_fg: Color::Rgb(33, 33, 33),
+        cursor: Color::Rgb(194, 24, 91),
+        placeholder: Color::Rgb(144, 164, 174),
+        error: Color::Rgb(211, 47, 47),
+        info: Color::Rgb(56, 142, 60),
+    }
+}
+
+// Helper functions for color serialization/deserialization
+
+fn deserialize_color<'de, D>(deserializer: D) -> Result<Color, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let s = String::deserialize(deserializer)?;
+    parse_color(&s).map_err(serde::de::Error::custom)
+}
+
+fn serialize_color<S>(color: &Color, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::Serializer,
+{
+    let s = color_to_string(color);
+    serializer.serialize_str(&s)
+}
+
+fn parse_color(s: &str) -> Result<Color, String> {
+    if let Some(hex) = s.strip_prefix('#') {
+        if hex.len() == 6 {
+            let r = u8::from_str_radix(&hex[0..2], 16)
+                .map_err(|_| format!("Invalid hex color: {}", s))?;
+            let g = u8::from_str_radix(&hex[2..4], 16)
+                .map_err(|_| format!("Invalid hex color: {}", s))?;
+            let b = u8::from_str_radix(&hex[4..6], 16)
+                .map_err(|_| format!("Invalid hex color: {}", s))?;
+            return Ok(Color::Rgb(r, g, b));
+        }
+    }
+
+    // Try named colors
+    match s.to_lowercase().as_str() {
+        "black" => Ok(Color::Black),
+        "red" => Ok(Color::Red),
+        "green" => Ok(Color::Green),
+        "yellow" => Ok(Color::Yellow),
+        "blue" => Ok(Color::Blue),
+        "magenta" => Ok(Color::Magenta),
+        "cyan" => Ok(Color::Cyan),
+        "gray" | "grey" => Ok(Color::Gray),
+        "darkgray" | "darkgrey" => Ok(Color::DarkGray),
+        "lightred" => Ok(Color::LightRed),
+        "lightgreen" => Ok(Color::LightGreen),
+        "lightyellow" => Ok(Color::LightYellow),
+        "lightblue" => Ok(Color::LightBlue),
+        "lightmagenta" => Ok(Color::LightMagenta),
+        "lightcyan" => Ok(Color::LightCyan),
+        "white" => Ok(Color::White),
+        _ => Err(format!("Unknown color: {}", s)),
+    }
+}
+
+fn color_to_string(color: &Color) -> String {
+    match color {
+        Color::Black => "black".to_string(),
+        Color::Red => "red".to_string(),
+        Color::Green => "green".to_string(),
+        Color::Yellow => "yellow".to_string(),
+        Color::Blue => "blue".to_string(),
+        Color::Magenta => "magenta".to_string(),
+        Color::Cyan => "cyan".to_string(),
+        Color::Gray => "gray".to_string(),
+        Color::DarkGray => "darkgray".to_string(),
+        Color::LightRed => "lightred".to_string(),
+        Color::LightGreen => "lightgreen".to_string(),
+        Color::LightYellow => "lightyellow".to_string(),
+        Color::LightBlue => "lightblue".to_string(),
+        Color::LightMagenta => "lightmagenta".to_string(),
+        Color::LightCyan => "lightcyan".to_string(),
+        Color::White => "white".to_string(),
+        Color::Rgb(r, g, b) => format!("#{:02x}{:02x}{:02x}", r, g, b),
+        _ => "#ffffff".to_string(),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_color_parsing() {
+        assert!(matches!(parse_color("#ff0000"), Ok(Color::Rgb(255, 0, 0))));
+        assert!(matches!(parse_color("red"), Ok(Color::Red)));
+        assert!(matches!(parse_color("lightblue"), Ok(Color::LightBlue)));
+    }
+
+    #[test]
+    fn test_built_in_themes() {
+        let themes = built_in_themes();
+        assert!(themes.contains_key("default_dark"));
+        assert!(themes.contains_key("gruvbox"));
+        assert!(themes.contains_key("dracula"));
+    }
+}

crates/owlen-core/src/ui.rs

@@ -23,6 +23,7 @@ pub enum InputMode {
     Visual,
     Command,
     SessionBrowser,
+    ThemeBrowser,
 }
 
 impl fmt::Display for InputMode {
@@ -36,6 +37,7 @@ impl fmt::Display for InputMode {
             InputMode::Visual => "Visual",
             InputMode::Command => "Command",
             InputMode::SessionBrowser => "Sessions",
+            InputMode::ThemeBrowser => "Themes",
         };
         f.write_str(label)
     }

crates/owlen-tui/src/chat_app.rs

@@ -2,6 +2,7 @@ use anyhow::Result;
 use owlen_core::{
     session::{SessionController, SessionOutcome},
     storage::{SessionMeta, StorageManager},
+    theme::Theme,
     types::{ChatParameters, ChatResponse, Conversation, ModelInfo, Role},
     ui::{AppState, AutoScroll, FocusedPanel, InputMode},
 };
@@ -61,8 +62,10 @@ pub struct ChatApp {
     storage: StorageManager,            // Storage manager for session persistence
     saved_sessions: Vec<SessionMeta>,   // Cached list of saved sessions
     selected_session_index: usize,      // Index of selected session in browser
-    save_name_buffer: String,           // Buffer for entering save name
     help_tab_index: usize,              // Currently selected help tab (0-4)
+    theme: Theme,                       // Current theme
+    available_themes: Vec<String>,      // Cached list of theme names
+    selected_theme_index: usize,        // Index of selected theme in browser
 }
 
 impl ChatApp {
@@ -77,6 +80,13 @@ impl ChatApp {
                 .expect("Failed to create fallback storage")
         });
 
+        // Load theme based on config
+        let theme_name = &controller.config().ui.theme;
+        let theme = owlen_core::theme::get_theme(theme_name).unwrap_or_else(|| {
+            eprintln!("Warning: Theme '{}' not found, using default", theme_name);
+            Theme::default()
+        });
+
         let app = Self {
             controller,
             mode: InputMode::Normal,
@@ -112,8 +122,10 @@ impl ChatApp {
             storage,
             saved_sessions: Vec::new(),
             selected_session_index: 0,
-            save_name_buffer: String::new(),
             help_tab_index: 0,
+            theme,
+            available_themes: Vec::new(),
+            selected_theme_index: 0,
         };
 
         (app, session_rx)
@@ -238,6 +250,9 @@ impl ChatApp {
             ("m", "Alias for model"),
             ("new", "Start a new conversation"),
             ("n", "Alias for new"),
+            ("theme", "Switch theme"),
+            ("themes", "List available themes"),
+            ("reload", "Reload configuration and themes"),
         ]
     }
 
@@ -312,6 +327,39 @@ impl ChatApp {
         self.help_tab_index
     }
 
+    pub fn available_themes(&self) -> &[String] {
+        &self.available_themes
+    }
+
+    pub fn selected_theme_index(&self) -> usize {
+        self.selected_theme_index
+    }
+
+    pub fn theme(&self) -> &Theme {
+        &self.theme
+    }
+
+    pub fn set_theme(&mut self, theme: Theme) {
+        self.theme = theme;
+    }
+
+    pub fn switch_theme(&mut self, theme_name: &str) -> Result<()> {
+        if let Some(theme) = owlen_core::theme::get_theme(theme_name) {
+            self.theme = theme;
+            // Save theme to config
+            self.controller.config_mut().ui.theme = theme_name.to_string();
+            if let Err(err) = config::save_config(self.controller.config()) {
+                self.error = Some(format!("Failed to save theme config: {}", err));
+            } else {
+                self.status = format!("Switched to theme: {}", theme_name);
+            }
+            Ok(())
+        } else {
+            self.error = Some(format!("Theme '{}' not found", theme_name));
+            Err(anyhow::anyhow!("Theme '{}' not found", theme_name))
+        }
+    }
+
     pub fn cycle_focus_forward(&mut self) {
         self.focused_panel = match self.focused_panel {
             FocusedPanel::Chat => {
@@ -1086,9 +1134,7 @@ impl ChatApp {
                     (KeyCode::Up, _) | (KeyCode::Char('k'), KeyModifiers::CONTROL) => {
                         // Navigate up in suggestions
                         if !self.command_suggestions.is_empty() {
-                            self.selected_suggestion = self
+                            self.selected_suggestion = self.selected_suggestion.saturating_sub(1);
-                                .selected_suggestion
-                                .saturating_sub(1);
                         }
                     }
                     (KeyCode::Down, _) | (KeyCode::Char('j'), KeyModifiers::CONTROL) => {
@@ -1122,9 +1168,14 @@ impl ChatApp {
                                 };
 
                                 // Generate description if enabled in config
-                                let description = if self.controller.config().storage.generate_descriptions {
+                                let description =
+                                    if self.controller.config().storage.generate_descriptions {
                                         self.status = "Generating description...".to_string();
-                                    match self.controller.generate_conversation_description().await {
+                                        match self
+                                            .controller
+                                            .generate_conversation_description()
+                                            .await
+                                        {
                                             Ok(desc) => Some(desc),
                                             Err(_) => None,
                                         }
@@ -1133,7 +1184,14 @@ impl ChatApp {
                                     };
 
                                 // Save the conversation with description
-                                match self.controller.conversation_mut().save_active_with_description(&self.storage, name.clone(), description) {
+                                match self
+                                    .controller
+                                    .conversation_mut()
+                                    .save_active_with_description(
+                                        &self.storage,
+                                        name.clone(),
+                                        description,
+                                    ) {
                                     Ok(path) => {
                                         self.status = format!("Session saved: {}", path.display());
                                         self.error = None;
@@ -1155,7 +1213,8 @@ impl ChatApp {
                                         return Ok(AppState::Running);
                                     }
                                     Err(e) => {
-                                        self.error = Some(format!("Failed to list sessions: {}", e));
+                                        self.error =
+                                            Some(format!("Failed to list sessions: {}", e));
                                     }
                                 }
                             }
@@ -1171,7 +1230,8 @@ impl ChatApp {
                                         return Ok(AppState::Running);
                                     }
                                     Err(e) => {
-                                        self.error = Some(format!("Failed to list sessions: {}", e));
+                                        self.error =
+                                            Some(format!("Failed to list sessions: {}", e));
                                     }
                                 }
                             }
@@ -1192,6 +1252,70 @@ impl ChatApp {
                                 self.controller.start_new_conversation(None, None);
                                 self.status = "Started new conversation".to_string();
                             }
+                            "theme" => {
+                                if args.is_empty() {
+                                    self.error = Some("Usage: :theme <name>".to_string());
+                                } else {
+                                    let theme_name = args.join(" ");
+                                    match self.switch_theme(&theme_name) {
+                                        Ok(_) => {
+                                            // Success message already set by switch_theme
+                                        }
+                                        Err(_) => {
+                                            // Error message already set by switch_theme
+                                        }
+                                    }
+                                }
+                            }
+                            "themes" => {
+                                // Load all themes and enter browser mode
+                                let themes = owlen_core::theme::load_all_themes();
+                                let mut theme_list: Vec<String> = themes.keys().cloned().collect();
+                                theme_list.sort();
+
+                                self.available_themes = theme_list;
+
+                                // Set selected index to current theme
+                                let current_theme = &self.theme.name;
+                                self.selected_theme_index = self
+                                    .available_themes
+                                    .iter()
+                                    .position(|name| name == current_theme)
+                                    .unwrap_or(0);
+
+                                self.mode = InputMode::ThemeBrowser;
+                                self.command_buffer.clear();
+                                self.command_suggestions.clear();
+                                return Ok(AppState::Running);
+                            }
+                            "reload" => {
+                                // Reload config
+                                match owlen_core::config::Config::load(None) {
+                                    Ok(new_config) => {
+                                        // Update controller config
+                                        *self.controller.config_mut() = new_config.clone();
+
+                                        // Reload theme based on updated config
+                                        let theme_name = &new_config.ui.theme;
+                                        if let Some(new_theme) =
+                                            owlen_core::theme::get_theme(theme_name)
+                                        {
+                                            self.theme = new_theme;
+                                            self.status = format!(
+                                                "Configuration and theme reloaded (theme: {})",
+                                                theme_name
+                                            );
+                                        } else {
+                                            self.status = "Configuration reloaded, but theme not found. Using current theme.".to_string();
+                                        }
+                                        self.error = None;
+                                    }
+                                    Err(e) => {
+                                        self.error =
+                                            Some(format!("Failed to reload config: {}", e));
+                                    }
+                                }
+                            }
                             _ => {
                                 self.error = Some(format!("Unknown command: {}", cmd));
                             }
@@ -1290,7 +1414,7 @@ impl ChatApp {
                     }
                     KeyCode::Tab | KeyCode::Right | KeyCode::Char('l') => {
                         // Next tab
-                        if self.help_tab_index < 4 {
+                        if self.help_tab_index < 5 {
                             self.help_tab_index += 1;
                         }
                     }
@@ -1305,6 +1429,7 @@ impl ChatApp {
                     KeyCode::Char('3') => self.help_tab_index = 2,
                     KeyCode::Char('4') => self.help_tab_index = 3,
                     KeyCode::Char('5') => self.help_tab_index = 4,
+                    KeyCode::Char('6') => self.help_tab_index = 5,
                     _ => {}
                 },
                 InputMode::SessionBrowser => match key.code {
@@ -1313,10 +1438,18 @@ impl ChatApp {
                     }
                     KeyCode::Enter => {
                         // Load selected session
-                        if let Some(session) = self.saved_sessions.get(self.selected_session_index) {
+                        if let Some(session) = self.saved_sessions.get(self.selected_session_index)
-                            match self.controller.conversation_mut().load_from_disk(&self.storage, &session.path) {
+                        {
+                            match self
+                                .controller
+                                .conversation_mut()
+                                .load_from_disk(&self.storage, &session.path)
+                            {
                                 Ok(_) => {
-                                    self.status = format!("Loaded session: {}", session.name.as_deref().unwrap_or("Unnamed"));
+                                    self.status = format!(
+                                        "Loaded session: {}",
+                                        session.name.as_deref().unwrap_or("Unnamed")
+                                    );
                                     self.error = None;
                                     // Update thinking panel
                                     self.update_thinking_from_last_message();
@@ -1340,11 +1473,14 @@ impl ChatApp {
                     }
                     KeyCode::Char('d') => {
                         // Delete selected session
-                        if let Some(session) = self.saved_sessions.get(self.selected_session_index) {
+                        if let Some(session) = self.saved_sessions.get(self.selected_session_index)
+                        {
                             match self.storage.delete_session(&session.path) {
                                 Ok(_) => {
                                     self.saved_sessions.remove(self.selected_session_index);
-                                    if self.selected_session_index >= self.saved_sessions.len() && !self.saved_sessions.is_empty() {
+                                    if self.selected_session_index >= self.saved_sessions.len()
+                                        && !self.saved_sessions.is_empty()
+                                    {
                                         self.selected_session_index = self.saved_sessions.len() - 1;
                                     }
                                     self.status = "Session deleted".to_string();
@@ -1357,6 +1493,48 @@ impl ChatApp {
                     }
                     _ => {}
                 },
+                InputMode::ThemeBrowser => match key.code {
+                    KeyCode::Esc | KeyCode::Char('q') => {
+                        self.mode = InputMode::Normal;
+                    }
+                    KeyCode::Enter => {
+                        // Apply selected theme
+                        if let Some(theme_name) = self
+                            .available_themes
+                            .get(self.selected_theme_index)
+                            .cloned()
+                        {
+                            match self.switch_theme(&theme_name) {
+                                Ok(_) => {
+                                    // Success message already set by switch_theme
+                                }
+                                Err(_) => {
+                                    // Error message already set by switch_theme
+                                }
+                            }
+                        }
+                        self.mode = InputMode::Normal;
+                    }
+                    KeyCode::Up | KeyCode::Char('k') => {
+                        if self.selected_theme_index > 0 {
+                            self.selected_theme_index -= 1;
+                        }
+                    }
+                    KeyCode::Down | KeyCode::Char('j') => {
+                        if self.selected_theme_index + 1 < self.available_themes.len() {
+                            self.selected_theme_index += 1;
+                        }
+                    }
+                    KeyCode::Home | KeyCode::Char('g') => {
+                        self.selected_theme_index = 0;
+                    }
+                    KeyCode::End | KeyCode::Char('G') => {
+                        if !self.available_themes.is_empty() {
+                            self.selected_theme_index = self.available_themes.len() - 1;
+                        }
+                    }
+                    _ => {}
+                },
             },
             _ => {}
         }

themes/README.md

@@ -0,0 +1,89 @@
+# OWLEN Built-in Themes
+
+This directory contains the built-in themes that are embedded into the OWLEN binary.
+
+## Available Themes
+
+- **default_dark** - High-contrast dark theme (default)
+- **default_light** - Clean light theme
+- **gruvbox** - Popular retro color scheme with warm tones
+- **dracula** - Dark theme with vibrant purple and cyan colors
+- **solarized** - Precision colors for optimal readability
+- **midnight-ocean** - Deep blue oceanic theme
+- **rose-pine** - Soho vibes with muted pastels
+- **monokai** - Classic code editor theme
+- **material-dark** - Google's Material Design dark variant
+- **material-light** - Google's Material Design light variant
+
+## Theme File Format
+
+Each theme is defined in TOML format with the following structure:
+
+```toml
+name = "theme-name"
+
+# Text colors
+text = "#ffffff"              # Main text color
+placeholder = "#808080"       # Placeholder/muted text
+
+# Background colors
+background = "#000000"        # Main background
+command_bar_background = "#111111"
+status_background = "#111111"
+
+# Border colors
+focused_panel_border = "#ff00ff"    # Active panel border
+unfocused_panel_border = "#800080"  # Inactive panel border
+
+# Message role colors
+user_message_role = "#00ffff"       # User messages
+assistant_message_role = "#ffff00"  # Assistant messages
+thinking_panel_title = "#ff00ff"    # Thinking panel title
+
+# Mode indicator colors (status bar)
+mode_normal = "#00ffff"
+mode_editing = "#00ff00"
+mode_model_selection = "#ffff00"
+mode_provider_selection = "#00ffff"
+mode_help = "#ff00ff"
+mode_visual = "#ff0080"
+mode_command = "#ffff00"
+
+# Selection and cursor
+selection_bg = "#0000ff"      # Selection background
+selection_fg = "#ffffff"      # Selection foreground
+cursor = "#ff0080"            # Cursor color
+
+# Status colors
+error = "#ff0000"             # Error messages
+info = "#00ff00"              # Info/success messages
+```
+
+## Color Format
+
+Colors can be specified in two formats:
+
+1. **Hex RGB**: `#rrggbb` (e.g., `#ff0000` for red, `#ff8800` for orange)
+2. **Named colors** (case-insensitive):
+   - **Basic**: `black`, `red`, `green`, `yellow`, `blue`, `magenta`, `cyan`, `white`
+   - **Gray variants**: `gray`, `grey`, `darkgray`, `darkgrey`
+   - **Light variants**: `lightred`, `lightgreen`, `lightyellow`, `lightblue`, `lightmagenta`, `lightcyan`
+
+**Note**: For colors not in the named list (like orange, purple, brown), use hex RGB format.
+
+OWLEN will display an error message on startup if a custom theme has invalid colors.
+
+## Creating Custom Themes
+
+To create your own theme:
+
+1. Copy one of these files to `~/.config/owlen/themes/`
+2. Rename and modify the colors
+3. Set `theme = "your-theme-name"` in `~/.config/owlen/config.toml`
+4. Or use `:theme your-theme-name` in OWLEN to switch
+
+## Embedding in Binary
+
+These theme files are embedded into the OWLEN binary at compile time using Rust's `include_str!()` macro. This ensures they're always available, even if the files are deleted from disk.
+
+Custom themes placed in `~/.config/owlen/themes/` will override built-in themes with the same name.

themes/default_dark.toml

@@ -0,0 +1,23 @@
+name = "default_dark"
+text = "white"
+background = "black"
+focused_panel_border = "lightmagenta"
+unfocused_panel_border = "#5f1487"
+user_message_role = "lightblue"
+assistant_message_role = "yellow"
+thinking_panel_title = "lightmagenta"
+command_bar_background = "black"
+status_background = "black"
+mode_normal = "lightblue"
+mode_editing = "lightgreen"
+mode_model_selection = "lightyellow"
+mode_provider_selection = "lightcyan"
+mode_help = "lightmagenta"
+mode_visual = "magenta"
+mode_command = "yellow"
+selection_bg = "lightblue"
+selection_fg = "black"
+cursor = "magenta"
+placeholder = "darkgray"
+error = "red"
+info = "lightgreen"

themes/default_light.toml

@@ -0,0 +1,23 @@
+name = "default_light"
+text = "black"
+background = "white"
+focused_panel_border = "#4a90e2"
+unfocused_panel_border = "#dddddd"
+user_message_role = "#0055a4"
+assistant_message_role = "#8e44ad"
+thinking_panel_title = "#8e44ad"
+command_bar_background = "white"
+status_background = "white"
+mode_normal = "#0055a4"
+mode_editing = "#2e8b57"
+mode_model_selection = "#b58900"
+mode_provider_selection = "#008b8b"
+mode_help = "#8e44ad"
+mode_visual = "#8e44ad"
+mode_command = "#b58900"
+selection_bg = "#a4c8f0"
+selection_fg = "black"
+cursor = "#d95f02"
+placeholder = "gray"
+error = "#c0392b"
+info = "green"

themes/dracula.toml

@@ -0,0 +1,23 @@
+name = "dracula"
+text = "#f8f8f2"
+background = "#282a36"
+focused_panel_border = "#ff79c6"
+unfocused_panel_border = "#44475a"
+user_message_role = "#8be9fd"
+assistant_message_role = "#ff79c6"
+thinking_panel_title = "#bd93f9"
+command_bar_background = "#44475a"
+status_background = "#44475a"
+mode_normal = "#8be9fd"
+mode_editing = "#50fa7b"
+mode_model_selection = "#f1fa8c"
+mode_provider_selection = "#8be9fd"
+mode_help = "#bd93f9"
+mode_visual = "#ff79c6"
+mode_command = "#f1fa8c"
+selection_bg = "#44475a"
+selection_fg = "#f8f8f2"
+cursor = "#ff79c6"
+placeholder = "#6272a4"
+error = "#ff5555"
+info = "#50fa7b"

themes/gruvbox.toml

@@ -0,0 +1,23 @@
+name = "gruvbox"
+text = "#ebdbb2"
+background = "#282828"
+focused_panel_border = "#fe8019"
+unfocused_panel_border = "#7c6f64"
+user_message_role = "#b8bb26"
+assistant_message_role = "#83a598"
+thinking_panel_title = "#d3869b"
+command_bar_background = "#3c3836"
+status_background = "#3c3836"
+mode_normal = "#83a598"
+mode_editing = "#b8bb26"
+mode_model_selection = "#fabd2f"
+mode_provider_selection = "#8ec07c"
+mode_help = "#d3869b"
+mode_visual = "#fe8019"
+mode_command = "#fabd2f"
+selection_bg = "#504945"
+selection_fg = "#ebdbb2"
+cursor = "#fe8019"
+placeholder = "#665c54"
+error = "#fb4934"
+info = "#b8bb26"

themes/material-dark.toml

@@ -0,0 +1,23 @@
+name = "material-dark"
+text = "#eeffff"
+background = "#263238"
+focused_panel_border = "#80cbc4"
+unfocused_panel_border = "#546e7a"
+user_message_role = "#82aaff"
+assistant_message_role = "#c792ea"
+thinking_panel_title = "#ffcb6b"
+command_bar_background = "#212b30"
+status_background = "#212b30"
+mode_normal = "#82aaff"
+mode_editing = "#c3e88d"
+mode_model_selection = "#ffcb6b"
+mode_provider_selection = "#80cbc4"
+mode_help = "#c792ea"
+mode_visual = "#f07178"
+mode_command = "#ffcb6b"
+selection_bg = "#546e7a"
+selection_fg = "#eeffff"
+cursor = "#ffcc00"
+placeholder = "#546e7a"
+error = "#f07178"
+info = "#c3e88d"

themes/material-light.toml

@@ -0,0 +1,23 @@
+name = "material-light"
+text = "#212121"
+background = "#eceff1"
+focused_panel_border = "#009688"
+unfocused_panel_border = "#b0bec5"
+user_message_role = "#448aff"
+assistant_message_role = "#7c4dff"
+thinking_panel_title = "#f57c00"
+command_bar_background = "#ffffff"
+status_background = "#ffffff"
+mode_normal = "#448aff"
+mode_editing = "#388e3c"
+mode_model_selection = "#f57c00"
+mode_provider_selection = "#009688"
+mode_help = "#7c4dff"
+mode_visual = "#d32f2f"
+mode_command = "#f57c00"
+selection_bg = "#b0bec5"
+selection_fg = "#212121"
+cursor = "#c2185b"
+placeholder = "#90a4ae"
+error = "#d32f2f"
+info = "#388e3c"

themes/midnight-ocean.toml

@@ -0,0 +1,23 @@
+name = "midnight-ocean"
+text = "#c0caf5"
+background = "#0d1117"
+focused_panel_border = "#58a6ff"
+unfocused_panel_border = "#30363d"
+user_message_role = "#79c0ff"
+assistant_message_role = "#89ddff"
+thinking_panel_title = "#9ece6a"
+command_bar_background = "#161b22"
+status_background = "#161b22"
+mode_normal = "#79c0ff"
+mode_editing = "#9ece6a"
+mode_model_selection = "#ffd43b"
+mode_provider_selection = "#89ddff"
+mode_help = "#ff739d"
+mode_visual = "#f68cf5"
+mode_command = "#ffd43b"
+selection_bg = "#388bfd"
+selection_fg = "#0d1117"
+cursor = "#f68cf5"
+placeholder = "#6e7681"
+error = "#f85149"
+info = "#9ece6a"

themes/monokai.toml

@@ -0,0 +1,23 @@
+name = "monokai"
+text = "#f8f8f2"
+background = "#272822"
+focused_panel_border = "#f92672"
+unfocused_panel_border = "#75715e"
+user_message_role = "#66d9ef"
+assistant_message_role = "#ae81ff"
+thinking_panel_title = "#e6db74"
+command_bar_background = "#272822"
+status_background = "#272822"
+mode_normal = "#66d9ef"
+mode_editing = "#a6e22e"
+mode_model_selection = "#e6db74"
+mode_provider_selection = "#66d9ef"
+mode_help = "#ae81ff"
+mode_visual = "#f92672"
+mode_command = "#e6db74"
+selection_bg = "#75715e"
+selection_fg = "#f8f8f2"
+cursor = "#f92672"
+placeholder = "#75715e"
+error = "#f92672"
+info = "#a6e22e"

themes/rose-pine.toml

@@ -0,0 +1,23 @@
+name = "rose-pine"
+text = "#e0def4"
+background = "#191724"
+focused_panel_border = "#eb6f92"
+unfocused_panel_border = "#26233a"
+user_message_role = "#31748f"
+assistant_message_role = "#9ccfd8"
+thinking_panel_title = "#c4a7e7"
+command_bar_background = "#26233a"
+status_background = "#26233a"
+mode_normal = "#9ccfd8"
+mode_editing = "#ebbcba"
+mode_model_selection = "#f6c177"
+mode_provider_selection = "#31748f"
+mode_help = "#c4a7e7"
+mode_visual = "#eb6f92"
+mode_command = "#f6c177"
+selection_bg = "#403d52"
+selection_fg = "#e0def4"
+cursor = "#eb6f92"
+placeholder = "#6e6a86"
+error = "#eb6f92"
+info = "#9ccfd8"

themes/solarized.toml

@@ -0,0 +1,23 @@
+name = "solarized"
+text = "#839496"
+background = "#002b36"
+focused_panel_border = "#268bd2"
+unfocused_panel_border = "#073642"
+user_message_role = "#2aa198"
+assistant_message_role = "#cb4b16"
+thinking_panel_title = "#6c71c4"
+command_bar_background = "#073642"
+status_background = "#073642"
+mode_normal = "#268bd2"
+mode_editing = "#859900"
+mode_model_selection = "#b58900"
+mode_provider_selection = "#2aa198"
+mode_help = "#6c71c4"
+mode_visual = "#d33682"
+mode_command = "#b58900"
+selection_bg = "#073642"
+selection_fg = "#93a1a1"
+cursor = "#d33682"
+placeholder = "#586e75"
+error = "#dc322f"
+info = "#859900"