Examine source code of Pretty Sweet

{
  "theme": {
    "images": {
      "theme_frame": "PrettysweetHCustom.jpg"
    },
    "colors": {
      "frame": "#ffff99",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Pretty  Sweet",
  "manifest_version": 2,
  "description": "abstract, bird, gold leaf, hearts, pink flowers, spring, summer, vines \n\nDesigned by MaDonna\n\nMy wallpaper to match is at: <a href=\"https://outgoing.prod.mozaws.net/v1/e9343a4f33d6659f1501223e88fa9b40b0f53028c8c770c36ad9c623ea36d4a6/http%3A//nature.desktopnexus.com/wallpaper/976158/\" rel=\"nofollow\">http://nature.desktopnexus.com/wallpaper/976158/</a>"
}