Examine source code of Mozilla Labs Persona

{
  "theme": {
    "images": {
      "theme_frame": "head7.png"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Mozilla Labs Persona",
  "manifest_version": 2,
  "description": "Mozilla Labs Persona made this using fireworks cs3 and quite proud of it too . this was made by greacelightning72 accept for the fox logo which was made by persona"
}