Examine source code of City Fog

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "City Fog",
  "manifest_version": 2,
  "description": "All credits to Sed_Rah\n<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/2223b939f06afb3ed31073787f58e6d4ef5461c7dce0b130a75f8a87340926d2/http%3A//www.deviantart.com/art/Berlin-Skyline-Widescreen-185693191\">http://www.deviantart.com/art/Berlin-Skyline-Widescreen-185693191</a>"
}