Examine source code of gris-bleu

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#77a7d1",
      "tab_background_text": "#8cbccf"
    }
  },
  "version": "2.0",
  "name": "gris-bleu",
  "manifest_version": 2,
  "description": "To go with Nightly Fox (Stylish for Firefox) \n<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/3ed01b8b9e237f798bc4263a5db697a13ea66c85a922cab16218c824872e6b2e/https%3A//userstyles.org/styles/116309/nightly-fox\">https://userstyles.org/styles/116309/nightly-fox</a>\nUpload your own: <a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/7ae9a6e7908ad7dcd4f386ccadd0681f97773835ff1921539ee636ceb2b3c4a5/https%3A//s-media-cache-ak0.pinimg.com/originals/0d/56/e9/0d56e9b6b702b1195b05e931e2a81886.png\">https://s-media-cache-ak0.pinimg.com/originals/0d/56/e9/0d56e9b6b702b1195b05e931e2a81886.png</a>"
}