toolbar button hover color change

Hi, I have a toolbar that adds toolbars dynamically. I want to know how to change the color of the toolbarbutton when I hover over it. Right now, it only turns a white/gray color. I can't seem to find a way to capture when a toolbarbutton is hovered over (only when the toolbar itself is hovered over) or find a property that sets the color. Is it possible to change the color when the button is hovered over and if so, how? Thanks

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