Examine source code of O

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "⠀⠀",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(255, 255, 255)",
      "toolbar_text": "rgb(147, 147, 147)",
      "frame": "rgb(255, 255, 255)",
      "tab_background_text": "rgb(147, 147, 147)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(64, 64, 64)",
      "tab_line": "rgb(255, 255, 255)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(147, 147, 147)",
      "button_background_active": "rgb(247, 247, 247)",
      "button_background_hover": "rgb(247, 247, 247)",
      "icons_attention": "rgb(0, 0, 0)",
      "icons": "rgb(157, 157, 157)",
      "popup_border": "rgb(255, 255, 255)",
      "popup_highlight_text": "rgb(170, 170, 170)",
      "popup_highlight": "rgb(247, 247, 247)",
      "sidebar_border": "rgb(238, 238, 238)",
      "sidebar": "rgb(255, 255, 255)",
      "tab_text": "rgb(155, 155, 155)",
      "toolbar_bottom_separator": "rgb(238, 238, 238)",
      "toolbar_field_border_focus": "rgb(255, 255, 255)",
      "toolbar_field_border": "rgb(238, 238, 238)",
      "toolbar_field_highlight": "rgb(241, 241, 241)",
      "toolbar_field_text_focus": "rgb(193, 193, 193)",
      "toolbar_top_separator": "rgb(238, 238, 238)",
      "tab_loading": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{df788ecc-f257-4310-8254-6133fb829de2}"
    }
  }
}