Examine source code of Ultimate Powder 2

{
  "theme": {
    "images": {
      "theme_frame": "Firefox_UP-Header2.jpg"
    },
    "colors": {
      "frame": "#1962ab",
      "tab_background_text": "#1962ab"
    }
  },
  "version": "2.0",
  "name": "Ultimate Powder 2",
  "manifest_version": 2,
  "description": "A persona for friends of Ultimate Powder - the white flaky stuff called snow :))"
}