Custom Ribbon Toggle Button, how do I change state with VBA?

I have a Toggle button that activates code that changes the fill color of the sheet. I want to send up a message box warning the user before it erases the fill in all their cells and if they hit cancel then the code should set the toggle button state back to unclicked and exit the sub. I cant figure out how to set the toggle button state, here is my code:

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Any help is appreciated
Thank you.

You need a getPressed callback that returns the appropriate state and your current code will need to invalidate the control.