Examine source code of Colourful Squares

{
  "theme": {
    "images": {
      "theme_frame": "main_bg.jpg"
    },
    "colors": {
      "frame": "#ff7300",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Colourful Squares",
  "manifest_version": 2,
  "description": "This skin is called Colourful Squares, well because it is some colourful squares. It really makes my browser stand out and hopefully will make yours too. =)"
}