Examine source code of Mount Rushmore

{
  "theme": {
    "images": {
      "theme_frame": "Mount-Rushmore_header.jpg"
    },
    "colors": {
      "frame": "#e7e7f3",
      "tab_background_text": "#fffed1"
    }
  },
  "version": "2.0",
  "name": "Mount Rushmore",
  "manifest_version": 2
}