About themes

CotEditor's theme is a collection of settings about editor's coloring. To customize themes:

  1. Choose CotEditor > Preferences.
  2. Select Appearances pane.
  3. Select the theme you want to customize from the theme list.

To use an existing theme as a guide for creating your own, select Duplicate in the action button (gear icon) instead. You can also export your own themes and import themes which are created by others.

Theme file format

CotEditor theme file must have the own extension “.cottheme” and its format is based on JSON with hex color values with # symbol.

See also