Theming

Themes are CSS files that define custom properties controlling the entire UI — colors, radii, terminal palette, editor highlighting, and diff colors. planeai ships with several bundled themes and supports custom themes.

Selecting a theme

Open Preferences (⌘, / Ctrl+,) and look under the Appearance section. Available themes appear as clickable buttons — select one to apply it immediately.

Alternatively, set the theme in your config file:

{
  "appearance": {
    "theme": "catppuccin",
  },
}

Theme file location

Themes live in ~/.config/planeai/themes/ (or %APPDATA%\planeai\themes\ on Windows). On first launch, planeai scaffolds this directory with the bundled themes. Any .css file you add here becomes available in the theme selector.

Bundled themes

Theme	Description
default	Monochrome design system (GitHub-inspired)
github	GitHub Light / Dark
catppuccin	Catppuccin Latte (light) / Macchiato (dark)
dracula	Dracula color palette
one	One Half Light / Dark

Color schemes

planeai bundles every color scheme that Ghostty ships, from iTerm2-Color-Schemes (MIT license). Each scheme belongs to its author, credited in the bundled CREDITS.md. In Preferences → Appearance, the Light and Dark dropdowns below the theme buttons set what each mode uses. Each lists the CSS themes first, tagged planeai, then the color schemes for that mode. Picking one mode keeps the other, so you can pair the default theme in light mode with a color scheme in dark mode. The theme buttons still apply one CSS theme to both modes.

With a color scheme, the terminal uses the scheme’s colors exactly. The rest of the UI (sidebar, panels, text, accent, diffs, and editor highlighting) is derived from the scheme, with a minimum text contrast enforced.

In the config file, theme is either a CSS theme name for both modes, or one entry per mode. An entry is a color scheme name, or { "css": "<name>" } for a CSS theme:

{
  "appearance": {
    "theme": { "light": { "css": "default" }, "dark": "Dracula" },
  },
}

If a mode’s theme cannot be found, that mode falls back to the built-in default colors.

To add your own scheme, drop a file in Ghostty’s theme format into ~/.config/planeai/themes/ghostty/. The file name is the scheme name, and a file with the same name as a bundled scheme replaces it.

Creating a custom theme

1. Copy an existing theme as a starting point:

   cp ~/.config/planeai/themes/default.css ~/.config/planeai/themes/my-theme.css

2. Edit the CSS custom properties in my-theme.css
3. Select “my-theme” in Preferences → Appearance

File structure

Each theme defines variables in :root (light mode) and .dark (dark mode):

:root {
  /* Light mode tokens */
  --color-canvas: #f4f4f6;
  --color-accent: #18181d;
  /* ... */
}

.dark {
  /* Dark mode tokens */
  --color-canvas: #171717;
  --color-accent: #f5f5f5;
  /* ... */
}

Token reference

UI role tokens

Token	Description
--color-canvas	Base page background
--color-chrome	Chrome/header background
--color-sidebar	Sidebar background
--color-main	Main content area background
--color-panel	Panel/card background
--color-panel-hi	Elevated panel (hover states, highlights)
--color-t1	Primary text
--color-t2	Secondary text
--color-t3	Muted text (hints, placeholders)
--color-border	Default border (subtle)
--color-border-s	Strong border (more visible)
--color-accent	Primary accent color
--color-on-accent	Text color on accent backgrounds
--color-accent-bg	Accent tint background (selections, highlights)
--color-scrim	Modal/overlay backdrop

Status colors

Token	Description
--color-status-running	Active/running indicator (green)
--color-status-review	Needs review indicator (amber)
--color-status-exited	Error/exited indicator (red)
--color-status-idle	Idle/inactive indicator (gray)

Radii

Token	Description
--radius-base	Small elements (buttons, inputs)
--radius-container	Large containers (cards, panels)

Terminal colors (16 ANSI + chrome)

Token	Description
--terminal-background	Terminal background
--terminal-foreground	Terminal foreground
--terminal-cursor	Cursor color
--terminal-selection	Selection background
--terminal-black	ANSI black
--terminal-red	ANSI red
--terminal-green	ANSI green
--terminal-yellow	ANSI yellow
--terminal-blue	ANSI blue
--terminal-magenta	ANSI magenta
--terminal-cyan	ANSI cyan
--terminal-white	ANSI white
--terminal-bright-*	Bright variants (×8)

Diff colors

Token	Description
--diff-add-bg	Added line background
--diff-del-bg	Deleted line background
--diff-add-color	Added line text color
--diff-del-color	Deleted line text color

Editor colors

Token	Description
--editor-background	Editor background
--editor-foreground	Editor text
--editor-selection	Selection background
--editor-line-number	Line number gutter
--editor-added	Added text in editor
--editor-deleted	Deleted text in editor
--editor-added-bg	Added line background in editor
--editor-deleted-bg	Deleted line background in editor

Syntax highlighting

Token	Description
--editor-keyword	Keywords (if, return, import)
--editor-string	String literals
--editor-comment	Comments
--editor-number	Numeric literals
--editor-variable	Variables
--editor-type	Type annotations
--editor-function	Function names
--editor-property	Object properties
--editor-operator	Operators
--editor-punctuation	Brackets, semicolons
--editor-meta	Meta/decorators

Minimal theme example

/* my-theme.css — Catppuccin-inspired custom theme */

:root {
  --color-canvas: #e6e9ef;
  --color-chrome: #e6e9ef;
  --color-sidebar: #e6e9ef;
  --color-main: #eff1f5;
  --color-panel: #eff1f5;
  --color-panel-hi: #dce0e8;
  --color-t1: #4c4f69;
  --color-t2: #6c6f85;
  --color-t3: #8c8fa1;
  --color-border: rgba(76, 79, 105, 0.08);
  --color-border-s: rgba(76, 79, 105, 0.15);
  --color-accent: #1e66f5;
  --color-on-accent: #eff1f5;
  --color-accent-bg: rgba(30, 102, 245, 0.1);
  --color-scrim: rgba(76, 79, 105, 0.3);
  --color-status-running: #40a02b;
  --color-status-review: #df8e1d;
  --color-status-exited: #d20f39;
  --color-status-idle: #9ca0b0;
  --radius-base: 0.5rem;
  --radius-container: 1rem;
  --terminal-background: #eff1f5;
  --terminal-foreground: #4c4f69;
  --terminal-cursor: #dc8a78;
}

.dark {
  --color-canvas: #1e2030;
  --color-chrome: #1e2030;
  --color-sidebar: #1e2030;
  --color-main: #24273a;
  --color-panel: #24273a;
  --color-panel-hi: #363a4f;
  --color-t1: #cad3f5;
  --color-t2: #a5adcb;
  --color-t3: #6e738d;
  --color-border: rgba(202, 211, 245, 0.08);
  --color-border-s: rgba(202, 211, 245, 0.14);
  --color-accent: #8aadf4;
  --color-on-accent: #24273a;
  --color-accent-bg: rgba(138, 173, 244, 0.12);
  --color-scrim: rgba(0, 0, 0, 0.55);
  --color-status-running: #a6da95;
  --color-status-review: #eed49f;
  --color-status-exited: #ed8796;
  --color-status-idle: #5b6078;
  --terminal-background: #24273a;
  --terminal-foreground: #cad3f5;
  --terminal-cursor: #f4dbd6;
}

Tips

Tip

Use high contrast between --color-canvas and --color-t1 for readability during long sessions.

Tip

You only need to override the tokens you want to change. Any token you omit falls back to the default theme’s value.

Note

Theme changes take effect immediately when selected in Preferences. Custom theme file edits require re-selecting the theme or restarting the app.