Examine source code of Rivr.me

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#969696",
      "tab_background_text": "#404040"
    }
  },
  "version": "2.0",
  "name": "Rivr.me",
  "manifest_version": 2,
  "description": "A persona for <a href=\"https://outgoing.prod.mozaws.net/v1/e4c22872d11dfd2ecb0f3cd4df7ec5b85c78545985aafe26ebf35e504a1d7c5d/http%3A//Rivr.me\" rel=\"nofollow\">Rivr.me</a>"
}