I wouldn't hesitate painting or whitewashing.. We just went through something similar. House was built in '60 with a 3/4 masonry wall, bricked with full foundation. It actually supports our ridge beams on the whole back side of the house (living room and dining room). The fireplace was built for either wood or gas, open to both rooms but, always over drafted when burning wood even with glass doors on the dining room side.
Was never a fan of the fake used brick look and we've lived with it for decades. Made the call to float and reface when we closed off the side to the dining room and installed an insert. Having said that, we re-introduced a MCM flavor back to the fireplace with dimensional stone and solid walnut mantle.
We're down to last 5% to finish the new living room and kitchen/dining. The new fireplace wall will get an accent color. Haven't chosen that yet.