Examine source code of Simple Spring

{
  "theme": {
    "images": {
      "theme_frame": "sweet-spring-header.jpg"
    },
    "colors": {
      "frame": "#bdbdbd",
      "tab_background_text": "#333333"
    }
  },
  "version": "2.0",
  "name": "Simple Spring",
  "manifest_version": 2,
  "description": "My first attempt at a persona."
}