Examine source code of Facebook On Firefox

{
  "theme": {
    "images": {
      "theme_frame": "header1.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Facebook On Firefox",
  "manifest_version": 2,
  "description": "this custom-made firefox persona is based on the social networking brand \"facebook\". incorporated into this persona inside the header is my facebook profile link, incase any one wants to add me."
}