Apply custom theme

{
  "display": {
    "title": true
  },
  "title": {
    "en": "Dark theme"
  },
  "theme": {
    "itemsBackground": "black",
    "colors": [
      "#FFB74D",
      "#FFEB3B",
      "#FF4081",
      "#40C4FF",
      "#66BB6A",
      "#BA68C8",
      "#FF5252",
      "#4DD0E1"
    ],
    "font": {
      "fontFamily": "Roboto",
      "fontSize": 16
    }
  }
}