Simple FadeOut

fadeOut.cs

void fadeOut(float duration, float delay){
  	_duration = duration;
		_delay = delay;
		Color colorTo = renderer.material.color;
		colorTo.a = 0;
		foreach (Material mat in renderer.materials)
        {
            HOTween.To(mat, duration, new TweenParms()
			            .Prop("color", colorTo)
			            .Ease(EaseType.EaseInOutQuad) // Ease
			            .OnUpdate( OnTweenUpdate )
						.Delay(delay)
			);
			fadeGlow(duration, 0, delay);
        }
	}