Examine source code of Escher-Metamorphosis

{
  "theme": {
    "images": {
      "theme_frame": "metamorphosis_top.jpg"
    },
    "colors": {
      "frame": "#99cccc",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Escher-Metamorphosis",
  "manifest_version": 2,
  "description": "based on the work by MC Escher"
}