Examine source code of INFECTED - Left4Dead

{
  "theme": {
    "images": {
      "theme_frame": "PersonaHeaderL4D01.jpg"
    },
    "colors": {
      "frame": "#aa6666",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "INFECTED - Left4Dead",
  "manifest_version": 2,
  "description": "Some of the Left 4 Dead Infected. Because even zombies need to customize their Firefox."
}