dotfiles

Theming Guide

The dotfiles ship a wallpaper-driven theme system that generates terminal color palettes directly from wallpaper images using K-Means clustering in CIELAB color space. One command changes the terminal, editor, window manager, GTK, desktop environment, wallpaper, and browser-facing color mode in under a second.

Themes are not hand-crafted — they are extracted from whatever wallpapers are available on the system.

How Themes Work

Wallpapers are the source of truth. The system discovers wallpapers from two locations:

  1. System wallpapers — platform-native (macOS /System/Library/Desktop Pictures/, Linux /usr/share/backgrounds/)
  2. Custom wallpapers — user-provided in ~/Pictures/Wallpapers/ (custom overrides system)

extract-theme.py extracts dominant colors from each wallpaper using K-Means clustering in CIELAB color space, then generates a full terminal palette (16 ANSI colors, accent, bg/fg, panel, border) with WCAG contrast enforcement.

rebuild-themes.sh orchestrates discovery → extraction → assembly into .chezmoidata/themes.toml. Themes are cached in ~/.cache/dotfiles/themes/ and only regenerated when wallpapers change.

The theme key in .chezmoidata.toml controls the active theme. Every template references the active theme’s data through ``.

Switching Themes

Interactive Picker

dot theme

Opens an fzf picker listing every paired wallpaper theme (themes that have both -dark and -light variants). Two columns: WALLPAPER name and SOURCE (System or Custom). The current theme is marked with and . Select one and press Enter.

Direct Switch

dot theme tahoe-dark

Sets the theme immediately. Regenerates configs and reloads running applications.

Rebuild Themes

dot theme rebuild           # incremental (uses cache for unchanged wallpapers)
dot theme rebuild --force   # full regeneration
dot theme rebuild --list    # discover wallpapers without rebuilding

Discovers wallpapers from system + custom paths, runs K-Means extraction in parallel (4 jobs), caches generated themes in ~/.cache/dotfiles/themes/, and writes .chezmoidata/themes.toml. Custom wallpapers override system wallpapers on name collision.

Under the Hood: dot-theme-sync

dot-theme-sync handles the full switching pipeline:

  1. Writes the new theme name into .chezmoidata.toml (and chezmoi.toml if present). If those files drift, dot-theme-sync now resynchronizes them before rendering because chezmoi.toml [data] overrides the source data file.
  2. Runs a targeted chezmoi apply on theme-dependent config files only – much faster than a full apply.
  3. Signals running applications to reload and coordinates browser-facing theme state:
dot-theme-sync                    # Reload current theme
dot-theme-sync macos-wave-light   # Switch to a new theme
dot-theme-sync --full             # Full chezmoi apply instead of targeted

What Changes

Each theme switch touches these applications:

Application Mechanism What Changes
Ghostty chezmoi apply + macOS app-support sync + DBus reload-config or runtime signal fallback Background, foreground, all 16 ANSI colors, cursor
Tmux chezmoi apply + source-file Status bar colors, pane borders, mode indicators
Niri chezmoi apply + load-config-file IPC Window borders, focus ring, inactive tint
Desktop (macOS) osascript + defaults write + killall System appearance (Light/Dark), accent color, highlight color; forces SystemUIServer/Dock/cfprefsd refresh
Wallpaper (macOS) osascript System Events Desktop wallpaper set across all displays
Wallpaper (Linux) gsettings / dms / swaybg / feh HEIC auto-converted to PNG; picture-uri and picture-uri-dark set separately
Desktop (Linux/GNOME) chezmoi apply + gsettings Theme name, icon theme, color scheme preference
Safari / Chrome / Edge Native browser appearance follows desktop theme Browser chrome stays aligned when using the default/native browser theme
Firefox chezmoi apply on ~/.config/firefox/user.js Website color scheme preference follows the active dot theme; link that file into a Firefox profile to enforce it
DMS sed -i on settings.json + IPC Stock theme mapped to accent family, dark/light mode
Neovim --remote-expr Lua eval over socket Colorscheme, style variant, background mode
VS Code chezmoi apply on settings.json workbench.colorTheme value
Alacritty chezmoi apply Full color block regeneration
Kitty chezmoi apply Full color block regeneration
WezTerm chezmoi apply Color scheme in Lua config

Dark/Light Toggle

dot theme toggle

Toggles between the dark and light variant of the current theme family. A theme named macos-tahoe-dark toggles to macos-tahoe-light, and vice versa.

Theme Families

Available themes depend on your system. Run dot theme list to see what’s discovered. On macOS Sonoma, you’ll see ~150+ themes from system wallpapers. Custom wallpapers in ~/Pictures/Wallpapers/ add more.

Rebuilding themes

When wallpapers change (new system update, new custom wallpapers), regenerate:

dot theme rebuild          # Regenerate (uses cache for unchanged wallpapers)
dot theme rebuild --force  # Force full regeneration
dot theme rebuild --list   # List discovered wallpapers without rebuilding

What works without wallpapers

Theme switching is a two-tier system:

Core (always works) — ships in the repo, no setup needed:

Wallpapers (optional) — user-provided, enhances the theme:

If no wallpapers are present, dot theme applies all core changes and skips the wallpaper step. No errors, no manual config.

Wallpapers (optional)

Wallpapers are not shipped in the repo. Each user sources their own and places them in ~/Pictures/Wallpapers/:

macos-tahoe-dark.heic
macos-tahoe-light.heic

The naming convention is macos-NAME-APPEARANCE.heic (or .jpg/.png). The theme picker marks themes with matching wallpapers as [W].

Wallpaper guidelines

Platform behavior

Platform Wallpaper support Mechanism
macOS .heic, .jpg, .png osascript (all desktops)
Linux (GNOME) .png, .jpg (.heic auto-converted) gsettings picture-uri + picture-uri-dark
Linux (Wayland) .png, .jpg (.heic auto-converted) swaybg, feh, or Niri/DMS IPC
WSL Not applicable No compositor; terminal colors still apply

On Linux, .heic files are automatically converted to .png using magick, heif-convert, or convert (whichever is available). The .png is cached and only regenerated when the source .heic changes.

Using your OS default wallpapers

If you don’t provide custom wallpapers, your OS keeps its current desktop wallpaper. The theme still applies all color changes (terminal, editor, accent, dark/light mode). This is the expected default for most users.

Build Artifacts

All build caches (Cargo, Go, pip, uv, Zig) are redirected to /tmp/builds/ via environment variables in mise.toml and cargo/config.toml. The directory is created on shell init via fish/conf.d/env.fish. Build artifacts are cleared on reboot.

Troubleshooting

Theme switch did not apply

Run a full apply to force all configs:

dot-theme-sync --full

Ghostty did not reload

Ghostty reloads via DBus (com.mitchellh.ghostty / reload-config). If DBus is unavailable, the fallback sends SIGUSR2 to the main process and also matches the macOS app bundle path when needed. Verify Ghostty is running:

pgrep -x ghostty

On macOS, Ghostty may also read ~/Library/Application Support/com.mitchellh.ghostty/config. dot-theme-sync now mirrors the regenerated XDG config into that location before reloading so the app-support override cannot keep an older palette active.

Neovim did not change colors

dot-theme-sync finds Neovim server sockets at /tmp/nvim*/0 and $XDG_RUNTIME_DIR/nvim.*.0. If Neovim runs with a custom --listen path, the auto-discovery misses it. Restart Neovim to pick up the new theme from the regenerated config.

GTK theme looks wrong

GTK theme names must match installed themes exactly. Catppuccin themes use names like catppuccin-mocha-blue-standard+default. Install the matching GTK theme package or fall back to Adwaita-dark / Adwaita.

macOS accent or appearance did not update

dot-theme-sync applies macOS appearance using osascript and accent via:

defaults write -g AppleAccentColor -int <value>

dot-theme-sync now kills cfprefsd, SystemUIServer, Dock, and System Settings after writing accent/highlight defaults to force an immediate refresh. If the UI still does not update, close and reopen System Settings.

Browser theme did not change

Safari, Chrome, and Edge are coordinated through the desktop theme, so custom browser themes can override what dot-theme-sync is trying to align. Switch those browsers back to their native/default theme if you want them to track macOS or GTK automatically.

Firefox uses the managed file at ~/.config/firefox/user.js. Link that file into your active Firefox profile as user.js if you want dot-theme-sync to control website prefers-color-scheme behavior:

ln -sf ~/.config/firefox/user.js ~/.mozilla/firefox/<profile>/user.js

tmux shows old colors

Tmux reloads via source-file. If TPM plugins override colors, run:

tmux source-file ~/.config/tmux/tmux.conf

Checking the active theme

grep '^theme = ' ~/.dotfiles/.chezmoidata.toml

This prints the current theme name. Cross-reference with dot theme list for available options.