I got an email recently from someone wanting to know color ideas to brighten up a too-brown living room. I can understand that dilemma all too well, since I used to have a drowning-in-brown living room myself. One of the colors I suggested adding in was gray. I still have a heavy dose of brown in my living room from the brown leather on the back and arms of the couch, and as I've been adding gray into the room through the ottoman, drapes, and DIY "For Like Ever" art, it's really helped to tone down the brown and make it look chic instead of frumpy (like too much brown can sometimes look).
Since brown is a warm color and gray is a cool one, it makes them a really good balance to each other.
I think this is such an attractive color combo. It's one that I like to wear, so it makes sense that I like it for my house too.