made this script.
itween (flash compatible).
with settings.
using UnityEngine;
using System.Collections;
public class TintLoop : MonoBehaviour
{
public Color Color;
public float Duration;
void Start ()
{
tk2dSprite sprite = GetComponent<tk2dSprite>();
Hashtable options = new Hashtable();
options.Add("from", sprite.color);
options.Add("to", Color);
options.Add("time", Duration);
options.Add("OnUpdate", "updateSpriteColor");
options.Add("looptype", iTween.LoopType.pingPong);
options.Add("easetype", iTween.EaseType.linear);
iTween.ValueTo(gameObject, options);
}
void updateSpriteColor(Color color)
{
tk2dSprite sprite = GetComponent<tk2dSprite>();
sprite.color = color;
}
}