Examine source code of John Deer

{
  "theme": {
    "images": {
      "theme_frame": "firefoxpersona1.png"
    },
    "colors": {
      "frame": "#aba805",
      "tab_background_text": "#e3df0c"
    }
  },
  "version": "2.0",
  "name": "John Deer",
  "manifest_version": 2,
  "description": "For lovers of the best make of tractor."
}