Grok Build draws all TUI colors from a central theme. You can switch themes while Grok is running, follow your operating system's light or dark appearance, and adjust scrollback layout, animations, and block styling through configuration files.
---
## Available Themes
Grok includes five built-in themes, plus an `auto` option that follows your system appearance:
| **GrokNight** | `groknight`, `grok-night`, `dark` | Neutral dark base with a magenta accent. Default theme. Survives quantization cleanly on 256-color and 16-color terminals. | No |
| **GrokDay** | `grokday`, `grok-day`, `light`, `day` | Light theme for bright terminal backgrounds. | No |
| **TokyoNight** | `tokyonight`, `tokyo-night`, `tokyo` | Dark, blue-tinted backgrounds from the Tokyo Night palette. Loses its character when quantized. | Yes |
| **RosePineMoon** | `rosepine`, `rose-pine`, `rosepine-moon`, `rose-pine-moon` | Muted dark palette with mauve accents, from the Rosé Pine family. | Yes |
| **OscuraMidnight** | `oscura`, `oscura-midnight` | Deep dark base with purple accents. | Yes |
Theme names are case-insensitive. The `auto` option (alias `system`) is documented under [Auto Theme (System Appearance)](#auto-theme-system-appearance).
### Minimal Mode Has No Theming
**Minimal mode** (`--minimal`) always renders with a single fixed terminal-native palette and ignores the `theme` settings entirely (they still apply to the full TUI). Minimal draws directly on your terminal's own background, so it uses your terminal's default foreground/background plus its 16-color ANSI palette — the same colors `git` or `ls` use — which stays readable on any light or dark terminal profile without detection or configuration. `/theme` and the theme rows in `/settings` are unavailable in minimal mode.
Syntax highlighting in minimal mode does **not** switch between light and dark theme files (polarity detection is intentionally avoided). Near-gray tokens inherit the terminal default foreground; chromatic tokens use base ANSI accents (red/green/yellow/blue/magenta/cyan) so read-file output and fenced code stay legible on both light and dark profiles.
Run the `/theme` slash command (alias `/t`) to open the theme picker. As you move through the list with the arrow keys, Grok previews each theme in real time. Press Enter to apply and save your choice, or press Escape to revert.
To switch without the picker, pass a name directly:
```
/theme tokyonight
```
Submitting `/theme` on its own -- without choosing from the picker -- cycles to the next theme.
### Via Config File
Set the theme in `~/.grok/config.toml`:
```toml
[ui]
theme = "tokyonight"
```
---
## Auto Theme (System Appearance)
Set `theme = "auto"` to have Grok follow your operating system's light/dark appearance and switch themes automatically:
```toml
[ui]
theme = "auto"
```
By default, dark mode maps to **GrokNight** and light mode maps to **GrokDay**. Override either mapping with `auto_dark_theme` and `auto_light_theme`:
```toml
[ui]
theme = "auto"
auto_dark_theme = "tokyonight"
auto_light_theme = "grokday"
```
`theme = "system"` is an alias for `theme = "auto"`.
### How Detection Works
| Platform | Method |
|----------|--------|
| **macOS** | Reads `AppleInterfaceStyle` system preference |
| **Windows** | Reads the system personalization registry |
| **SSH / headless** | Falls back to an OSC 11 terminal background query at startup |
Once running, Grok polls for appearance changes every 5 seconds. Toggling your OS between light and dark mode takes effect within seconds without restarting.
### Via the Settings Pane
Run `/settings` (alias `/config`) and open the **Appearance** category to set the **Auto dark theme** and **Auto light theme** interactively. Selecting `auto` in the `/theme` picker enables auto mode using these mappings.
---
## Color Support Detection
On startup, Grok detects your terminal's color capability level:
| Level | Description | Detection |
|-------|-------------|-----------|
| **Truecolor** (24-bit) | Full RGB color. All themes render as designed. | `COLORTERM=truecolor` or equivalent terminal capability |
| **256-color** | Indexed palette. RGB values are mapped to the nearest palette entry. | Standard xterm-256color |
| **16-color** | ANSI names only. Colors are mapped to the closest ANSI color. | Basic terminal support |
When you set `NO_COLOR`, Grok emits no color and renders in monochrome.
Run `/doctor` to see the detected color level and the themes available on this terminal. If truecolor is unavailable, Doctor shows the relevant setup steps or explains the terminal limitation.
Every theme is defined using full RGB values. At startup, Grok quantizes all colors to match the detected capability level. This means:
- On **truecolor** terminals, colors pass through unchanged.
- On **256-color** terminals, each RGB value is mapped to the nearest indexed palette entry.
- On **16-color** terminals, colors map to ANSI names.
GrokNight and GrokDay use neutral grays that quantize cleanly. TokyoNight, RosePineMoon, and OscuraMidnight use distinctive tinted backgrounds that lose their character when quantized, which is why the theme picker hides them on non-truecolor terminals.
### Runtime-Generated Colors
Colors generated at runtime (syntax highlighting, background blending) are also quantized through the same pipeline, ensuring consistent appearance across all terminal types.
---
## Cursor Color
Grok sets your terminal cursor to the current theme's `accent_user` color using the OSC 12 escape sequence, to indicate an active Grok session. The cursor color is:
- Applied on startup and on theme switch.
- Reset to the terminal's default on exit via OSC 112.
This works in terminals that support OSC 12 (most modern terminals).
---
## Compact Mode
Toggle compact mode with the `/compact-mode` slash command. Compact mode:
- Removes outer vertical padding (top/bottom margins become 0).
- Reduces horizontal padding to the minimum (1 column).
- Reduces top padding in the prompt area and info blocks.
The setting is persisted in `~/.grok/config.toml` under `[ui].compact_mode` and survives restarts.
Use compact mode on small screens to maximize content area.
---
## Syntax Highlighting
Grok bundles three `.tmTheme` files for code-block syntax highlighting and selects one based on the active theme:
-`grok-night.tmTheme` -- GrokNight, RosePineMoon, and OscuraMidnight
-`grok-day.tmTheme` -- GrokDay
-`tokyo-night.tmTheme` -- TokyoNight
Grok selects the matching file automatically when you switch themes. The `.tmTheme` files are built into the binary, so you cannot replace them with your own.
---
## Deep Customization with pager.toml
For fine-grained control over the TUI appearance, create `~/.grok/pager.toml`. This file controls scrollback layout, block styling, animations, and more. All settings have defaults; specify only the values you override. (Dev builds generate this file as a template with every default commented out — uncomment a line to override it; commented values keep tracking future defaults.)
### Layout
Control viewport padding and block spacing:
```toml
[scrollback.layout]
outer_vpad = 1 # Vertical padding (top/bottom) for the viewport
outer_hpad_left = 2 # Left margin (minimum: 1)
outer_hpad_right = 2 # Right margin (minimum: 1)
block_pad_left = 2 # Padding between accent line and content
block_pad_right = 2 # Padding after content at right edge
```
### Scrollbar
```toml
[scrollback.scrollbar]
enabled = true # Show/hide the scrollbar
gap_left = 0 # Gap between content and scrollbar (0 = adjacent)
gap_right = 0 # Gap between scrollbar and screen edge (0 = at edge)
# scrollbar_bg = "none" # Override background color (or "none" for theme default)
# scrollbar_fg = "none" # Override thumb color (or "none" for theme default)