Examine source code of Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(32, 40, 46)",
      "toolbar_text": "rgb(235, 238, 241)",
      "frame": "rgb(15, 19, 22)",
      "tab_background_text": "rgb(186, 199, 208)",
      "toolbar_field": "rgb(15, 19, 22)",
      "toolbar_field_text": "rgb(144, 164, 179)",
      "tab_line": "rgb(28, 35, 40)",
      "popup": "rgb(15, 19, 22)",
      "popup_text": "rgb(186, 199, 208)",
      "button_background_active": "rgb(44, 56, 65)",
      "button_background_hover": "rgb(44, 56, 65)",
      "frame_inactive": "rgb(15, 19, 22)",
      "icons_attention": "rgb(235, 238, 241)",
      "icons": "rgb(235, 238, 241)",
      "ntp_background": "rgb(12, 16, 19)",
      "ntp_text": "rgb(235, 238, 241)",
      "popup_border": "rgb(15, 19, 22)",
      "popup_highlight_text": "rgb(235, 238, 241)",
      "popup_highlight": "rgb(32, 40, 46)",
      "sidebar_border": "rgb(32, 40, 46)",
      "sidebar_highlight_text": "rgb(144, 164, 179)",
      "sidebar_highlight": "rgb(15, 19, 22)",
      "sidebar_text": "rgb(235, 238, 241)",
      "sidebar": "rgb(32, 40, 46)",
      "tab_selected": "rgb(32, 40, 46)",
      "tab_text": "rgb(235, 238, 241)",
      "toolbar_bottom_separator": "rgb(32, 40, 46)",
      "toolbar_field_border_focus": "rgb(144, 164, 179)",
      "toolbar_field_border": "rgb(15, 19, 22)",
      "toolbar_field_focus": "rgb(15, 19, 22)",
      "toolbar_field_highlight_text": "rgb(255, 255, 255)",
      "toolbar_field_highlight": "rgb(65, 82, 95)",
      "toolbar_field_text_focus": "rgb(186, 199, 208)",
      "toolbar_top_separator": "rgb(15, 19, 22)",
      "toolbar_vertical_separator": "rgb(235, 238, 241)",
      "tab_loading": "rgb(28, 35, 40)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a0007266-9bd8-4dae-b381-34e4f7365726}"
    }
  }
}