Tool Button Icon Color Changes

magicstar

Hi,
I want to have effect like VLC Play Pause Button. Based on other posts, I have

Have resource file with play pause icons(transparent background)
Have created checkable toolbutton.
Have assigned icon for normal off/on through qt designer

However,
when it is checked(or clicked), the icon turns slightly grey. I do not want this behaviour. I am not sure, what is causing this behaviour as well.
Can someone please guide me