Examine source code of Firefox on tiles

{
  "theme": {
    "images": {
      "theme_frame": "tiles-firefox-header.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Firefox on tiles",
  "manifest_version": 2,
  "description": "Using The Gimp I created a large mosaic tiled background, through red, pink and orange colours and a little soft glow for some well deserved ethereal-ness! Plop the Firefox 3 logo to the right, a little dark glow and position for centrality and bob is your uncle."
}