Examine source code of Deep Dungeon

{
  "theme": {
    "images": {
      "theme_frame": "dungeon_header.JPG"
    },
    "colors": {
      "frame": "#9c9999",
      "tab_background_text": "#262626"
    }
  },
  "version": "2.0",
  "name": "Deep Dungeon",
  "manifest_version": 2,
  "description": "Pillars in a dungeon lit up by torch light."
}