Examine source code of OpenMedia.ca

{
  "theme": {
    "images": {
      "theme_frame": "FFskin.png"
    },
    "colors": {
      "frame": "#dbdbdb",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "OpenMedia.ca",
  "manifest_version": 2,
  "description": "Dress your browser up with <a href=\"https://outgoing.prod.mozaws.net/v1/d67598d1be19753560e8c298ea1d9cb9cc32048aabfe09f4931c5422df3a4eb2/http%3A//OpenMedia.ca\" rel=\"nofollow\">OpenMedia.ca</a>'s persona!"
}