Examine source code of Jena City

{
  "theme": {
    "images": {
      "theme_frame": "jena-top.jpg"
    },
    "colors": {
      "frame": "#808080",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Jena City",
  "manifest_version": 2,
  "description": "Jena (Thuringia, Germany). Photo looking at the city from the south. Provided by the authors of the Yana Framework for PHP."
}