Examine source code of Amsterdam roofscape

{
  "theme": {
    "images": {
      "theme_frame": "SMAdaktop.jpg"
    },
    "colors": {
      "frame": "#030303",
      "tab_background_text": "#e8b2b2"
    }
  },
  "version": "2.0",
  "name": "Amsterdam roofscape",
  "manifest_version": 2,
  "description": "Roofscape in Amsterdam. Looking at the Van Gogh Museum and Rijksmuseum"
}