Texture/Material changes but is not reflected in the game world

I'm trying to change a texture of each instantiated prefab and they're all coming out the same color. If I inspect each of the instances, each has a different material/shader assigned to it with the different color. I'm guessing I'm doing something wrong but I can't figure out where.

 var clone = Instantiate(prefab) as GameObject;
 var texture = textures[Random.Range(0, textures.Length - 1)];
 clone.GetComponent<Renderer>().material.mainTexture = texture;
 clones.Add (clone);