public Tweener DOGradient(int charIndex, VertexGradient endValue, float duration)
        {
            NotifyActiveColorTween();
            ProxyColor proxy = GetProxyColor(charIndex);

            return(proxy.AddTween(proxy.DOColorGradient(endValue, duration)));
        }
        // Color tweens
        public Tweener DOFade(int charIndex, float endValue, float duration)
        {
            NotifyActiveColorTween();
            ProxyColor proxy = GetProxyColor(charIndex);

            return(proxy.AddTween(proxy.DOFade(endValue, duration)));
        }