How do I change the colour of buttons?

Like the title says, how do I change the colour when pressed and stays on that colour until you press another button and that previous one changed to the original colour.

Let’s say the button 1 is black. When pressed, it become white and stays white. Until I press button 2 , button 2 turned white and button 1 change to black.

So how do I do this? And I’ve already changed the style of the button,

- YouTube might help you

or this one seems easier PTV Unreal Engine 4 Blueprints tutorial 2 (Dynamic Material Instances) - YouTube