Examine source code of Firefox 3.6 Theme

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Firefox 3.6 Theme",
  "manifest_version": 2,
  "description": "A theme that looks a lot like Firefox 3.6. Although this doesn't unfortunately change the buttons, it still gives a 3.6 feel none the less. Obviously, I personally take no credit for it as I Mozilla designed this. Not me."
}