Examine source code of Astolfo x3

{
  "name": "Astolfo x3",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "astolfo border nostars.png"
    },
    "colors": {
      "frame": "rgb(254, 240, 239)",
      "tab_background_text": "rgb(140, 89, 87)",
      "toolbar": "rgba(160, 106, 106, 0.01)",
      "bookmark_text": "rgb(140, 89, 87)",
      "toolbar_field": "rgba(160, 106, 106, 0.76)",
      "toolbar_field_text": "rgb(254, 240, 239)",
      "tab_line": "rgb(140, 89, 87)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b13b02be-06a3-4ad2-9597-f87585f38c6f}"
    }
  }
}