Examine source code of Deadly Checkerboard

{
  "theme": {
    "images": {
      "theme_frame": "checkers_head.jpg"
    },
    "colors": {
      "frame": "#ed2828",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Deadly Checkerboard",
  "manifest_version": 2,
  "description": "Soft checkers with playful red accents.  Made with GIMP, with help from Hawksmont's wonderful brush sets."
}