Examine source code of Impromptu

{
  "theme": {
    "images": {
      "theme_frame": "bokhdr.jpg"
    },
    "colors": {
      "frame": "#969696",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Impromptu",
  "manifest_version": 2,
  "description": "Sometimes the best things come to those that wait. Sometimes the waiting's the best part. Some parts of things are weighty. So, to clarify, use impromptu."
}