Examine source code of Firefox 3 mod

{
  "theme": {
    "images": {
      "theme_frame": "header.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#bac"
    }
  },
  "version": "2.0",
  "name": "Firefox 3 mod",
  "manifest_version": 2,
  "description": "Hate the new firefox look? use this mod of the old firefox to make it look like firefox 3"
}