Examine source code of Gotham City

{
  "name": "Gotham City",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Apple iMac.jpg"
    },
    "colors": {
      "frame": "rgba(139, 144, 156, 1)",
      "tab_background_text": "rgba(237, 224, 109, 1)",
      "toolbar": "rgba(94, 92, 92, 1)",
      "bookmark_text": "rgba(240, 200, 56, 1)",
      "toolbar_field": "rgba(237, 235, 130, 1)",
      "toolbar_field_text": "rgba(70, 93, 115, 1)"
    }
  }
}