constructor(r, g, b, a) {
    super();
    this.r = clamp(r);
    this.g = clamp(g);
    this.b = clamp(b);
    this.a = clampAlpha(a);
    this.name = '';
    this.rgba = this;
  }
Initialize a new `RGBA` with the given r,g,b,a component values.

@param {Number} r
@param {Number} g
@param {Number} b
@param {Number} a
@api public