Examine source code of Pyro and co.

{
  "theme": {
    "images": {
      "theme_frame": "Firefoxskinheadercopy.png"
    },
    "colors": {
      "frame": "#ff0000",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Pyro and co.",
  "manifest_version": 2,
  "description": "I had to cut out the stars, the extra text, and most of the gradient on the background to fit this... my fursona, my sister's, and a few of our characters, meant for our use only, but I changed my mind and anyone can use it if they like it."
}