set( r, g, b, a = 1 ) {

		this.a = a;

		return super.set( r, g, b );

	}
Overwrites the default to honor alpha.
You can also pass a single THREE.Color, hex or
string argument to this method.

@param {number|string|Color} r - The red value.
@param {number} g - The green value.
@param {number} b - The blue value.
@param {number} [a=1] - The alpha value.
@return {Color4} A reference to this object.