Examine source code of Animated Clouds

{
  "theme": {
    "images": {
      "theme_frame": "header_sky.png"
    },
    "colors": {
      "frame": "#33ccff",
      "tab_background_text": "#2b3b47"
    }
  },
  "version": "2.0",
  "name": "Animated Clouds",
  "manifest_version": 2,
  "description": "A subtle animated Persona.  Yes, you can animate them with either animated GIFs or aPNGs!"
}