Examine source code of Old Map

{
  "theme": {
    "images": {
      "theme_frame": "Mozz_old_map_Header_TEMPLATE.jpg"
    },
    "colors": {
      "frame": "#c9b15c",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Old Map",
  "manifest_version": 2,
  "description": "Travel to past"
}