Examine source code of FutureRPG

{
  "theme": {
    "images": {
      "theme_frame": "Untitled-111111.jpg"
    },
    "colors": {
      "frame": "#c9c9c9",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "FutureRPG",
  "manifest_version": 2,
  "description": "<a href=\"https://outgoing.prod.mozaws.net/v1/3d7f65671e52972c40a38d9c39fd40147d669977f10fed4409354cfb73603249/http%3A//Future-RPG.com\" rel=\"nofollow\">Future-RPG.com</a> Firefox Theme"
}