Examine source code of Freshly Green

{
  "theme": {
    "images": {
      "theme_frame": "mozilla_personasPersonal.png"
    },
    "colors": {
      "frame": "#999999",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Freshly Green",
  "manifest_version": 2,
  "description": "Persona made from my web's background. Relaxing color, and plessant to the eye. Simple is the key!"
}