Examine source code of Yello

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#fdbe02",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Yello",
  "manifest_version": 2,
  "description": "Credit to <a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/6f097e82ec6a64ea854d674c64fd5dd3a3107cddeab0d6dde33e0d8d9845434c/http%3A//psdgraphics.com\">psdgraphics.com</a> for this great background theme.\n\n<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/cf002c43a754c9833ea11ff107bb2e65ba42b08c4fdb7ac632808f7e4d5c7dac/http%3A//www.psdgraphics.com/backgrounds/gray-and-yellow-photoshop-patterns/\">http://www.psdgraphics.com/backgrounds/gray-and-yellow-photoshop-patterns/</a>"
}