Examine source code of Cockatiel

{
  "theme": {
    "images": {
      "theme_frame": "archimedes.jpg"
    },
    "colors": {
      "frame": "#ffff66",
      "tab_background_text": "#ffff66"
    }
  },
  "version": "2.0",
  "name": "Cockatiel",
  "manifest_version": 2,
  "description": "A picture I took of my Cockatiel, Archimedes."
}