Examine source code of DigiCert Dark

{
  "theme": {
    "images": {
      "theme_frame": "PersonaDarkHeader.jpg"
    },
    "colors": {
      "frame": "#c2c2c2",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "DigiCert Dark",
  "manifest_version": 2,
  "description": "Show your DigiCert pride by using this dark persona. See more at <a href=\"https://outgoing.prod.mozaws.net/v1/d84791085735e0e3d95bfe997ead697cdb8e4ea8f7af10f2b6bb09c3f6815cd4/http%3A//www.digicert.com\" rel=\"nofollow\">www.digicert.com</a>"
}