Assuming you are talking about painting the brick fireplace surround, I would suggest these couple of options.

A clean white would brighten up the room, like this:

modern metal fire place cover · More Info

If the white is too stark, you could also go with a distressed look while keeping the white color, like this:

Breezy Brentwood · More Info

Or, for a bit of contrast, paint the brick a rich gray, deeper than the tone you are using for the walls, like this:

New Kitchen · More Info

Best of luck on your project!