Question MRTK changing Button Color on Button Pressed

Hello there. I'm just trying to achieve that a button is disabled for a second after it is pressed or at least color it red for that time.

I tried to achieve it with this script:

Code (CSharp):

1.     public void OnButtonPressed()
2.     {
3.         GameObject cylinder = GameObject.FindWithTag("Button");
4.        
5.        
6.         if(cylinder != null)
7.         {
8.             var cylinderRenderer = cylinder.GetComponent<Renderer>();
9.  
10.  
11.             cylinderRenderer.material.SetColor("_Color", Color.red);
12.         }
13.     }

It's the PressableRoundButton Prefab of the MRTK. On this button, there are already existing events and I thought that I can call my script method after the event is triggered and change the color but it does not work (the method is called):


The material for the inner part of the button is in a cylinder:


What am I doing wrong?