Examine source code of Vector blue

{
  "theme": {
    "images": {
      "theme_frame": "Persona1.jpg"
    },
    "colors": {
      "frame": "#cccccc",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Vector blue",
  "manifest_version": 2,
  "description": "A simple blue gradient plus an image blended from <a href=\"https://outgoing.prod.mozaws.net/v1/b357023622b44e449a9cf7f8c659b68721bec92752d8283b65c7b571f9a61207/http%3A//Vectorportal.com\" rel=\"nofollow\">Vectorportal.com</a>"
}