Examine source code of Afterglow

{
  "theme": {
    "images": {
      "theme_frame": "hdafterglow.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#bababa"
    }
  },
  "version": "2.0",
  "name": "Afterglow",
  "manifest_version": 2,
  "description": "Firefox Persona version of my “Afterglow” wallpaper.\n\n3D artwork by Ryan Bliss.\n\nPersona Designed by Mark Hamilton for Digital Blasphemy.\n\nWallpaper available at <a href=\"https://outgoing.prod.mozaws.net/v1/e725658c91b15e73937dbb3f81b1670094fb88c0c4fab0788a5d09fd7e4463c1/http%3A//digitalblasphemy.com/preview.shtml%3Fi=afterglow2k92\" rel=\"nofollow\">http://digitalblasphemy.com/preview.shtml?i=afterglow2k92</a>"
}