Examine source code of Minecraft End Portal

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#aba8a8",
      "tab_background_text": "#f0e7e7"
    }
  },
  "version": "2.0",
  "name": "Minecraft End Portal",
  "manifest_version": 2,
  "description": "It is the end portal in the popular indie game Minecraft, it looks cool and space-like."
}