Examine source code of Protostar

{
  "theme": {
    "images": {
      "theme_frame": "protostarhd3.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Protostar",
  "manifest_version": 2,
  "description": "Firefox Persona version of my “Protostar” wallpaper. 3D artwork by Ryan Bliss. Persona Designed by Mark Hamilton for Digital Blasphemy. Wallpaper available at <a href=\"https://outgoing.prod.mozaws.net/v1/dccc6380910f5205f64a5cb984af9e04f9e50ff56f0bff04795faf4cb989856e/http%3A//digitalblasphemy.com/preview.shtml%3Fi=protostar\" rel=\"nofollow\">http://digitalblasphemy.com/preview.shtml?i=protostar</a>"
}