Examine source code of xkcd logo

{
  "theme": {
    "images": {
      "theme_frame": "xkcd.png"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#6e7b91"
    }
  },
  "version": "2.0",
  "name": "xkcd logo",
  "manifest_version": 2,
  "description": "An unofficial xkcd persona.  I wanted one but the only other available one had \"xkcd\" written wrong, which annoyed me so I made a new one."
}