Examine source code of Howrse

{
  "theme": {
    "images": {
      "theme_frame": "Howrsebanner1_edited-1.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#107326"
    }
  },
  "version": "2.0",
  "name": "Howrse",
  "manifest_version": 2,
  "description": "A Banner to show your love for the website, <a href=\"https://outgoing.prod.mozaws.net/v1/b3d2a1dd828dd85e2fd0077de356551c8446ce45279ab2a6e4d88805d1c45cbb/http%3A//Howrse.com\" rel=\"nofollow\">Howrse.com</a> \n:)"
}