Examine source code of UW.com

{
  "theme": {
    "images": {
      "theme_frame": "mozillapersonaUW2.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#f6fa05"
    }
  },
  "version": "2.0",
  "name": "UW.com",
  "manifest_version": 2,
  "description": "<a href=\"https://outgoing.prod.mozaws.net/v1/c988227df176076aab1f2f629765f291b332409fa02606bc4ac370287352820f/http%3A//Underground-World.com\" rel=\"nofollow\">Underground-World.com</a>"
}