Examine source code of Colours

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Colours",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(204, 185, 123)",
      "toolbar_text": "rgb(98, 102, 183)",
      "frame": "rgb(215, 12, 8)",
      "tab_background_text": "rgb(231, 13, 187)",
      "toolbar_field": "rgb(211, 21, 95)",
      "toolbar_field_text": "rgb(8, 223, 220)",
      "tab_line": "rgb(6, 162, 223)",
      "popup": "rgb(231, 210, 7)",
      "popup_text": "rgb(188, 28, 194)",
      "tab_loading": "rgb(6, 162, 223)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fe0c9b4d-e8ad-431c-9583-cedd892ff86a}"
    }
  }
}