Examine source code of Peak Light

{
  "theme": {
    "images": {
      "theme_frame": "firefoxheader.jpg"
    },
    "colors": {
      "frame": "#c97d0a",
      "tab_background_text": "#695819"
    }
  },
  "version": "2.0",
  "name": "Peak Light",
  "manifest_version": 2,
  "description": "Peak District landscape"
}