Examine source code of Firefox 5 years

{
  "theme": {
    "images": {
      "theme_frame": "persona2.jpg"
    },
    "colors": {
      "frame": "#e8dcdc",
      "tab_background_text": "#fafafa"
    }
  },
  "version": "2.0",
  "name": "Firefox 5 years",
  "manifest_version": 2,
  "description": "A persona to celebrate five years (and counting) with Firefox."
}