Changing building colors?

How can i change color of building??? I try this... Its does not works((

Code:

void OnEntityBuilt(Planner plan, GameObject go)
     {
            ChangeEntityColor(go);
     }void ChangeEntityColor(GameObject go) {
      go.AddComponent<MeshRenderer>();
      Material newMaterial = new Material(Shader.Find("Specular"));      newMaterial.color = Color.red;
      go.GetComponent<MeshRenderer>().material = newMaterial;
        }

 

afaik you are not able to change the clients colour when trying to place a deployable / building part