Examine source code of Colorful Light Effect

{
  "theme": {
    "images": {
      "theme_frame": "Header.png"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Colorful Light Effect",
  "manifest_version": 2,
  "description": "A \"colorful light effect\" :\nSee <a href=\"https://outgoing.prod.mozaws.net/v1/ca2828c71796040a7af6cf6b0c5b53d2f20360b641034472f3c5d96957527435/http%3A//abduzeedo.com/reader-tutorial-colorful-light-effect-gimp\" rel=\"nofollow\">http://abduzeedo.com/reader-tutorial-colorful-light-effect-gimp</a> to create this effect too :)"
}