Examine source code of A Rainbow City

{
  "name": "A Rainbow City",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "RainbowCityH.jpg"
    },
    "colors": {
      "frame": "rgba(123, 189, 247, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(121, 186, 247, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(121, 186, 247, 0.05)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7d684c8c-e41e-4295-94a5-00b2d7374c09}"
    }
  }
}