Examine source code of Saving Energy

{
  "theme": {
    "images": {
      "theme_frame": "personatop.png"
    },
    "colors": {
      "frame": "#c9c9c9",
      "tab_background_text": "#999999"
    }
  },
  "version": "2.0",
  "name": "Saving Energy",
  "manifest_version": 2,
  "description": "This persona saves energy because a given monitor requires more power to display a white (or light) screen than a black (or dark) screen."
}