Examine source code of Purple Iris

{
  "theme": {
    "images": {
      "theme_frame": "purpleirisheader.JPG"
    },
    "colors": {
      "frame": "#ad6af5",
      "tab_background_text": "#cfad00"
    }
  },
  "version": "2.0",
  "name": "Purple Iris",
  "manifest_version": 2,
  "description": "A close-up of a purple iris."
}