I am hesitant to recommend an accent wall without actually being in the room; it's too hard to get a feel for what "wants to be" the focal point. So I'd probably stick with a mid-tone gray like Ben Moore Revere Pewter or Sherwin Williams Worldly Gray. Two caveats: your fireplace brick looks pretty yellow, so to contrast with that properly, the gray will need to have adequate depth. If you are having trouble getting enough contrast without going too dark on the wall, you might look at a gray-blue instead, such as SW 6232 Misty. On my monitor, your side chair appears almost pink, and the couch, a very pinky brown. If that's the case in real life, I feel the lime accents are fighting those tones. I hope not, because otherwise I love your palette. Finally, on the art - I'd consider something with a touch of gold to keep the space from going too icy. I love the attached piece, called Love Force Field: it's bold, without being too busy. Hope that helps.

Thanks for the recommendations. I'll try to get some more natural light pictures to upload. The side chair and couch are actual a stonish color. This is the couch fabric http://www.klaussner.com/Klaussner-Chenille-Body-Cloth/JAZZ%20STONE-328/CoverInformation.aspx