Examine source code of Why blue.

{
  "theme": {
    "images": {
      "theme_frame": "why-blue-top.jpg"
    },
    "colors": {
      "frame": "#3f768c",
      "tab_background_text": "#3f768c"
    }
  },
  "version": "2.0",
  "name": "Why blue.",
  "manifest_version": 2,
  "description": "Enjoy.\nVisit my website: <a href=\"https://outgoing.prod.mozaws.net/v1/e8a3e84bc9c1f6b5cf9afe8a7a3deec54673a0597a8e5bd836a58f659e6388b9/http%3A//folksnetdesktop.com/\" rel=\"nofollow\">http://folksnetdesktop.com/</a>"
}