Examine source code of Portal Theme 3

{
  "theme": {
    "images": {
      "theme_frame": "cube-hotpink4.jpg"
    },
    "colors": {
      "frame": "#ff4000",
      "tab_background_text": "#008ad4"
    }
  },
  "version": "2.0",
  "name": "Portal Theme 3",
  "manifest_version": 2,
  "description": "Portal Improved again, hopefully perfect!"
}