Examine source code of Marble Top

{
  "theme": {
    "images": {
      "theme_frame": "Marble.png"
    },
    "colors": {
      "frame": "#c9c9c9",
      "tab_background_text": "#c0c0c0"
    }
  },
  "version": "2.0",
  "name": "Marble Top",
  "manifest_version": 2,
  "description": "This looks like a marble counter top. The design is set up for use with small Icons in your Tool bars Rt click \"Customize\" section."
}