Examine source code of Uranian Blue

{
  "name": "Uranian Blue",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "1x1-00000000.png"
    },
    "colors": {
      "frame": "rgba(227, 242, 253, 1)",
      "tab_background_text": "rgba(51, 93, 153, 1)",
      "toolbar": "rgba(187, 222, 251, 1)",
      "bookmark_text": "rgba(51, 93, 153, 1)",
      "toolbar_field": "rgba(144, 202, 249, 1)",
      "toolbar_field_text": "rgba(51, 93, 153, 1)",
      "tab_line": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4af0064a-e7e0-48a2-b6cd-8193836ae826}"
    }
  }
}