Examine source code of Tombstone Horizon

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#3a4704",
      "tab_background_text": "#c2e01b"
    }
  },
  "version": "2.0",
  "name": "Tombstone Horizon",
  "manifest_version": 2,
  "description": "This is my take on a bright red horizon that silhouettes some long forgotten tombstones.  It's something different, so I hope you like it. :-)"
}