Hi Catherine I have never done this so I researched this article for you
would love to see your finished project, good luck!
Hi Catherine! Personally, I wouldn't paint marble. Could it be cleaned or refinished? Maybe remove it and replace it with something you like better?
Catherine: This link may be helpful
The marble can be stained with concrete/masonry stain. It’s like dye and won’t peel and won’t burn from being too close to the firebox.