Examine source code of Envidia

{
  "theme": {
    "images": {
      "theme_frame": "test4.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#303030"
    }
  },
  "version": "2.0",
  "name": "Envidia",
  "manifest_version": 2,
  "description": "Envidia Gilde, <a href=\"https://outgoing.prod.mozaws.net/v1/1e481c833dba66a1fb35c9df56cd45ed5c90a3a4e3f8a44e520bdae430d4d318/http%3A//www.envidia.eu\" rel=\"nofollow\">www.envidia.eu</a>, Design by Raskop,"
}