Examine source code of Abyss

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Abyss",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(49, 49, 49)",
      "toolbar_text": "rgb(249, 249, 249)",
      "frame": "rgb(18, 18, 18)",
      "tab_background_text": "rgb(184, 184, 184)",
      "toolbar_field": "rgb(40, 40, 40)",
      "toolbar_field_text": "rgb(249, 249, 249)",
      "tab_line": "rgb(154, 154, 154)",
      "popup": "rgb(56, 56, 56)",
      "popup_text": "rgb(249, 249, 249)",
      "button_background_active": "rgb(30, 30, 30)",
      "button_background_hover": "rgb(79, 79, 79)",
      "frame_inactive": "rgb(26, 26, 26)",
      "icons": "rgb(211, 211, 211)",
      "popup_border": "rgb(30, 30, 30)",
      "popup_highlight_text": "rgb(249, 249, 249)",
      "toolbar_field_border_focus": "rgb(40, 40, 40)",
      "tab_loading": "rgb(154, 154, 154)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9e64c7cf-5ad4-4645-b306-8a676858a7e8}"
    }
  }
}