Examine source code of Middle Earth map

{
  "theme": {
    "images": {
      "theme_frame": "MiddleEarthskin.JPG"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Middle Earth map",
  "manifest_version": 2,
  "description": "A map of Tolkien's Middle Earth from The Lord of the Rings, centred on the Shire."
}