Hi, I am trying to help design a living room for a friend. He has a big open floor plan with bright, but neutral yellow walls. There is tons of natural light in the space but he is looking to paint one wall. We picked the perfect wall but he is concerned about a darker color closing up the space. I had in mind a few nice greens because he tends to hang gallery style frames (imagine close together and many different sizes). How do I remedy his concerns?