Examine source code of Storm at Sea..

{
  "theme": {
    "images": {
      "theme_frame": "StormatSeaH.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Storm at Sea..",
  "manifest_version": 2,
  "description": "Thanks to the photography of Dylan O'Donnell. (<a href=\"https://outgoing.prod.mozaws.net/v1/2c7991d04d6f0b22fe6898ba100967436085327ccff7d39b8ec671e1af670be7/http%3A//deography.com/\" rel=\"nofollow\">http://deography.com/</a>) sea, ocean, sky, clouds, stormy, dark, The matching wallpaper can be found at:  <a href=\"https://outgoing.prod.mozaws.net/v1/95ee582e523dffe65bd839a3d60d61ba3ef3d095cbeecf84d767c435eafff774/http%3A//nature.desktopnexus.com/wallpaper/606197/\" rel=\"nofollow\">http://nature.desktopnexus.com/wallpaper/606197/</a>"
}