I think it looks great as is.

The Contracter told me that that is the color of the brick it's gray

OMGoodness I love the brick DO NOT PAINT!

@webster, once you add the n furniture and decor, the brick won't look so overwhelming. If you want to hang art on the wall, use a picture molding, that goes up like crown molding but has a lip that holds a hook on wire that is attached to the picture frame.

The brick wall will add a lot of character and charm to the office. Keep it, paint everything else a clean crisp white, use the grays in the bricks for flooring tone inspiration. To cover it, you'll give away some of the charm.

It's nice, but it is also a large surface. I would break up with either good sized art or wall mounted bookshelves with a good thick trim painted white? But the brick is pretty nice, will make a good backdrop

You could also consider painting shelves or wood trim black. Would be very striking over this brick.