Examine source code of Firefox 3D Effect

{
  "theme": {
    "images": {
      "theme_frame": "MyCreatedFFHeader.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#000"
    }
  },
  "version": "2.0",
  "name": "Firefox 3D Effect",
  "manifest_version": 2,
  "description": "This is my first ever persona , i hope you like it ! and i've added a cool 3d bevel effect!"
}