Hi! So I'm not much help with paint color, but wanted to share two things that we did which you might consider: first, we got a high-heat black spraypaint (Rustoleum from Home Depot) and painted the fireplace face plate (the brass part) black, which instantly updated our fireplaces for about $10; second, I did not care for our red brick fireplace, and hand-painted it to look like a different color of brick. Without priming, I hand painted each brick Benjamin Moore Eagle Rock, then sponged on a lighter grey (Willow Creek) and a darker grey (Ironhorse, I think). Later, I decided it needed some brown, so I sponged on a bit of watered down brown paint (can't remember the color). I took care not to get paint on the mortar. The whole project took about a day. It came out great and I get tons of complements. If you are at all hesitant about getting the "painted brick" look when you do it all in one color, I would consider tying this method first. 99% of people would not know that the brick had been painted. If you don't like the way it turns out, you can always go back to your original plan!

Hi again- I'm an Aussie and the term 'wood burner' means a metal box with a glass door on the front and in the situation where you have a 'double sided wood burner' that means two glass doors on each end. A wood burning fireplace open either side between two rooms is a different thing. Sorry about the confusion. I looked into building one of those in brick and was strongly advised to place a glass panel on one side ( as Ironwood has pointed out) the natural draughts that move through your home will take the smoke with it. A piece of glass will prevent this from happening.

A Rumford design is very shallow, has outward-flaring sides, a back that arches forward, a curve on the underside of the front lintel leading back to a broad slot-like flue with a flue chamber above it. The overall front opening is almost square, sometimes slightly taller than wide. Rumford fireplaces are very distinctive looking. You can get some basic information from this wikipedia article here: https://en.wikipedia.org/wiki/Rumford_fireplace and there is plenty of info online, even ready-made reproductions (more or less accurate). Rumford developed his improvements and published them in the late 1790s, just before fireplace heating was displaced by stove heating (a process already well underway when Rumford developed his improvements). Good luck with your whatever you decide to do.

wall set up with electric fireplace in great room