setBgColor(color = '#000000') {
    if (!this.bgCanvas) {
      const { bgSize = 400 } = this.conf;
      this.bgCanvas = createCanvas(bgSize, bgSize);
    }
    CanvasUtil.fillRect({ canvas: this.bgCanvas, color });

    if (this.background) this.display.removeChild(this.background);
    this.background = new Sprite(Texture.fromCanvas(this.bgCanvas));
    this.display.addChildAt(this.background, 0);
  }
Set background color
@param {string} bgcolor - background color
@public