Examine source code of Best Turtle

{
  "theme": {
    "images": {
      "theme_frame": "Unbenannt-1.jpg"
    },
    "colors": {
      "frame": "#545454",
      "tab_background_text": "#d6d6d6"
    }
  },
  "version": "2.0",
  "name": "Best Turtle",
  "manifest_version": 2,
  "description": "best turtle!"
}