Examine source code of Books - Somewhere Else

{
  "theme": {
    "images": {
      "theme_frame": "SomewhereElse_Headerweb.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Books - Somewhere Else",
  "manifest_version": 2,
  "description": "For all the booklovers out there. For all those who rather be reading than online.\nQuote by Mark Twain."
}