Examine source code of Ubuntu Ambience

{
  "theme": {
    "images": {
      "theme_frame": "personas-header.png"
    },
    "colors": {
      "frame": "#f0ebe2",
      "tab_background_text": "#f0ebe2"
    }
  },
  "version": "2.0",
  "name": "Ubuntu Ambience",
  "manifest_version": 2,
  "description": "Fits with the new Ubuntu theme Ambience. It is dark and has no gradient."
}