J.T.
I'm not in real estate, but I've never heard of a painted fireplace hurting resale. Our living room originally had dark picture frame paneling and brick fireplace matching the outside brick. Ewwww! I imagine it was SOOOO dark in there. Previous owners painted everything white, and it is gorgeous. It is so bright in there. EVERYONE compliments our house when they come in. I say PAINT IT!!! (You can definitely do it yourself, too!)