Examine source code of firefox rotaro

{
  "theme": {
    "images": {
      "theme_frame": "ff-ani.png"
    },
    "colors": {
      "frame": "#b3b1b1",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "firefox rotaro",
  "manifest_version": 2,
  "description": "Fire-Fox rotiert"
}