Examine source code of Cobalt Black

{
  "name": "Cobalt Black",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "blue-surface-1680x1050-wallpaper-1693.jpg"
    },
    "colors": {
      "frame": "rgba(10, 10, 10, 1)",
      "tab_background_text": "rgba(13, 81, 148, 1)",
      "toolbar": "rgba(71, 128, 186, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(125, 167, 219, 1)",
      "toolbar_field_text": "rgba(77, 77, 77, 1)",
      "tab_line": "rgba(252, 252, 252, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9b996dc2-4891-4605-b308-90bf37b4cfba}"
    }
  }
}