Examine source code of Cyril & Marcus

{
  "theme": {
    "images": {
      "theme_frame": "cyril_marcus_mozilla_header.jpg"
    },
    "colors": {
      "frame": "#f7f4f4",
      "tab_background_text": "#030303"
    }
  },
  "version": "2.0",
  "name": "Cyril & Marcus",
  "manifest_version": 2,
  "description": "art by <a href=\"https://outgoing.prod.mozaws.net/v1/debf462e30e2a959f4b1521854a8b6a4d92a4ec4ecccef7d3591922f342f7454/http%3A//schrod1ng3r.deviantart.com\" rel=\"nofollow\">schrod1ng3r.deviantart.com</a>\n\nCharacters (c) schrod1ng3r and ra-san"
}