updateMatrixWorld() {

		this.scale.set( 0.5 * this.light.width, 0.5 * this.light.height, 1 );

		if ( this.color !== undefined ) {

			this.material.color.set( this.color );
			this.children[ 0 ].material.color.set( this.color );

		} else {

			this.material.color.copy( this.light.color ).multiplyScalar( this.light.intensity );

			// prevent hue shift
			const c = this.material.color;
			const max = Math.max( c.r, c.g, c.b );
			if ( max > 1 ) c.multiplyScalar( 1 / max );

			this.children[ 0 ].material.color.copy( this.material.color );

		}

		// ignore world scale on light
		this.matrixWorld.extractRotation( this.light.matrixWorld ).scale( this.scale ).copyPosition( this.light.matrixWorld );

		this.children[ 0 ].matrixWorld.copy( this.matrixWorld );

	}
The helper's color. If `undefined`, the helper will take the color of the light.

@type {number|Color|string|undefined}