Examine source code of half life header

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ff8000",
      "tab_background_text": "#ffa91f"
    }
  },
  "version": "2.0",
  "name": "half life header",
  "manifest_version": 2,
  "description": "Live out your childhood fantasy of a legendary PC game."
}