Examine source code of Belphegor and Leviathan

{
  "theme": {
    "images": {
      "theme_frame": "Untitltyytyed-1.jpg"
    },
    "colors": {
      "frame": "#b8b8b8",
      "tab_background_text": "#870c08"
    }
  },
  "version": "2.0",
  "name": "Belphegor and Leviathan",
  "manifest_version": 2,
  "description": "Belphegor and Leviathan from Umineko No Naku Koro Ni."
}