Examine source code of L4D2 Apocalypse Time

{
  "theme": {
    "images": {
      "theme_frame": "L4D2-persona.jpg"
    },
    "colors": {
      "frame": "#fcf4f4",
      "tab_background_text": "#fcfcfc"
    }
  },
  "version": "2.0",
  "name": "L4D2 Apocalypse Time",
  "manifest_version": 2,
  "description": "The apocalypse time begin ! Will you survive in this dark Internet world ?"
}