Examine source code of Summer 2011

{
  "theme": {
    "images": {
      "theme_frame": "summer.jpg"
    },
    "colors": {
      "frame": "#ff0000",
      "tab_background_text": "#0afaea"
    }
  },
  "version": "2.0",
  "name": "Summer 2011",
  "manifest_version": 2
}