Custom Themes

Copy custom-theme.json to Sidra's user data directory, then edit its colours.

File location

Platform	File
Linux	~/.config/Sidra/custom-theme.json
macOS	~/Library/Application Support/Sidra/custom-theme.json
Windows	%APPDATA%\Sidra\custom-theme.json

On Linux, a set XDG_CONFIG_HOME replaces ~/.config.

A valid file adds one Custom Theme choice under Style in Settings. Select it once. Saved edits apply without a restart, including in an open Settings window.

Enable Noctalia's Sidra community template and select Settings → Style → Custom Theme once. Sidra then follows Noctalia's active colour palette automatically.

Colour format

The example contains all 12 required colours in dark:

{
  "dark": {
    "base": "#1e1e2e",
    "mantle": "#181825",
    "crust": "#11111b",
    "surface0": "#313244",
    "surface1": "#45475a",
    "surface2": "#585b70",
    "overlay": "#6c7086",
    "text": "#cdd6f4",
    "subtext1": "#bac2de",
    "subtext0": "#a6adc8",
    "accent": "#f38ba8",
    "accentHover": "#eba0ac"
  }
}

Use six-digit hex colours, such as #1e1e2e. JSON requires double quotes and accepts no comments or trailing commas. For a separate light scheme, add a light object with the same 12 keys. Without it, Sidra uses dark in both modes.

Keys	Colour role
base, mantle, crust	Page, player and footer backgrounds
surface0, surface1, surface2	Controls, scrollbars and borders
text, subtext1, subtext0, overlay	Primary, secondary, emphasised secondary and tertiary text
accent, accentHover	Highlight colour and its hover or pressed state

Sidra accepts low-contrast palettes without adjustment. Choose colours that you can read comfortably. Custom themes change colours only, not fonts or layout.

If the file is missing, unreadable or invalid, Custom Theme disappears and an active custom theme falls back to Apple Music. Fix or restore the file to recover the theme automatically, unless you selected another style.

Migrating from custom CSS

Sidra ignores existing custom.css files but leaves them untouched. Copy your colours into the JSON example. Sidra cannot automatically convert arbitrary CSS, and CSS rules no longer apply.