After changing multiple buttons highlight color, buttons dissapear on click.

I want to give my players the option of changing some of the menu colors incl the button highlights and even though it took me quite some headscratching i made a function that succesfully changes the highlights of all buttons in my list but there's a weird side effect, now buttons dissapear on click and then briefly show the highlight while re-appearing back to normal state.

I don't understand what's going on at all and there's no errors.

All buttons have the default Color Tint Transition And here's my code:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine.UI;
 
 public List<Color> Colors = new List<Color>();
 public List<Button> Buttons = new List<Button>();
 
 public void ButtonHighlights(int colorSelected){
         int count = Buttons.Count;
         while(count != 0){
             count--;
             Button b = Buttons[count].GetComponent<Button>(); 
             ColorBlock cb = b.colors;
             cb.highlightedColor = Colors[colorSelected];
             b.colors = cb;
         }
     }

If anyone has any ideas, please share them! The code is based on code by @PeterMu Link: http://answers.unity3d.com/questions/792008/how-to-change-normal-color-highlighted-color-etc-i.html Thanks in advance.