Examine source code of Colorful grid of GridArea

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#3a474d"
    }
  },
  "version": "2.0",
  "name": "Colorful grid of GridArea",
  "manifest_version": 2,
  "description": "a patterned background from my blog.\n<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/2ea413426fd0f55187acf687976963537cc66957e96b13a0b228c11926f6f496/http%3A//gridarea.tistory.com\">http://gridarea.tistory.com</a>\ndone with Inkscape"
}