Examine source code of Working Cat

{
  "name": "NFS",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "ezgif-42c93e78e02f02.gif"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(72, 150, 137, 1)",
      "toolbar": "rgba(158, 60, 60, 0)",
      "bookmark_text": "rgba(49, 130, 106, 1)",
      "toolbar_field": "rgba(158, 44, 44, 0)",
      "toolbar_field_text": "rgba(57, 158, 133, 1)",
      "tab_line": "rgba(128, 5, 5, 0.92)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{51e10c76-b5a1-45f0-a83a-e30d69e79696}"
    }
  }
}