Examine source code of Postcards from London

{
  "theme": {
    "images": {
      "theme_frame": "postcards_from_london_header.jpg"
    },
    "colors": {
      "frame": "#e52439",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Postcards from London",
  "manifest_version": 2,
  "description": "These aren't real postcards. I've created them from photos I took."
}