//uzycie:
new TweenValueTo<SpriteRenderer>(new SpriteRenderer())
            .Add("from", 1)
            .Add("to", 5)
            .Add("time", 10)
            .Start();

        TweenValueTo<TextMesh> tvt = new TweenValueTo<TextMesh>(new TextMesh());
        tvt.Add("from", 1)
           .Add("to", 5)
           .Add("time", 10)
           .Start();
//klasa:
public class TweenValueTo<T>  {
    private Hashtable tweenParams;
    private T target;

    public TweenValueTo(T target) {
        this.target = target;
        tweenParams = new Hashtable();
        tweenParams.Add("onupdate", "OnColorUpdated");
    }

    public TweenValueTo<T> Add(string property, object value) {
        tweenParams.Add(property, value);
        return this;
    }

    private void OnColorUpdated(Color color) {
        if (target is SpriteRenderer)
            (target as SpriteRenderer).color = color;
        else if (target is TextMesh)
            (target as TextMesh).color = color;
    }

    public void Start() {
        iTween.ValueTo(target.gameObject, tweenParams);
    }
}