Themes

applanch ships with three built-in themes and supports fully custom theme palettes.

Built-in Themes

Theme	Description
Follow system	Automatically switches between Light and Dark based on the Windows setting
Light	Light background, dark text
Dark	Dark background (navy), light text

Switch themes in Settings under Appearance → Theme.

Custom Themes

Built-in themes are loaded from Config/theme-palette.json. Add your own themes under Config/UserDefined/theme-palette/*.json.

For the full JSON field reference, see Theme JSON Format.

Editing Themes With Theme Creator

Distribute applanch.ThemeCreator together with applanch when you want end users to adjust colors themselves. The tool now works as a simple theme editor:

1. Open Theme Creator without arguments.
2. Choose a base theme such as light or dark.
3. Enter a theme ID and display names.
4. Edit colors in the Theme Colors table.
5. Save the file to the suggested Config/UserDefined/theme-palette/<theme-id>.json path.

The saved file is still a normal JSON file, so users can fine-tune it later in any text editor.

Representative Brush Keys

Brush key	Used for
Brush.AppBackground	Main window background
Brush.Surface	Cards, menus, and dialog surfaces
Brush.TextPrimary	Primary text and prominent monochrome icons
Brush.TextSecondary	Secondary text and metadata
Brush.ItemBackground	Launcher item cards and list rows
Brush.ItemBorder	Borders around cards, inputs, and list items
Brush.NotificationWarningBorder	Warning notification accents
Brush.DialogError	Error dialog icon color

Start with these keys when building a user-facing theme, then refine the remaining brushes if needed.

Adding a Custom Theme

1. Create a JSON file under Config/UserDefined/theme-palette/ (for example my-theme.json).
2. Define your custom themes in that file.
3. Restart applanch.

{
  "themes": [
    {
      "id": "my-theme",
      "displayNames": {
        "en": "My Theme",
        "ja": "マイテーマ"
      },
      "entries": [
        { "key": "Brush.AppBackground", "hex": "#1E1E2E" },
        { "key": "Brush.Surface",       "hex": "#27273A" }
      ]
    }
  ]
}

The file is merged with built-in themes, so you only need to define what you want to add or override.

Referencing Another Theme

Instead of specifying entries directly, set entriesFrom to inherit all brush values from an existing theme:

• Use a string value when one theme should always inherit from the same source theme.
• Use an object with light and dark when the source theme should change with the Windows light/dark mode.
• The referenced theme ID can be either a built-in theme such as light / dark, or a custom theme ID that you defined in another JSON file.

This is useful when you want to add an alias theme or reuse an existing palette without repeating the full entries list.

Always inherit from a single theme:

{
  "id": "my-light-copy",
  "displayNames": { "en": "My Light Copy" },
  "entriesFrom": "light"
}

Switch the inherited theme based on the Windows color mode:

{
  "id": "my-dark-variant",
  "displayNames": { "en": "Dark Variant" },
  "entriesFrom": {
    "light": "light",
    "dark": "dark"
  }
}

When the Windows setting is light, the light source theme ID is used; when dark, the dark source theme ID is used. This is how the built-in Follow system theme works.