One option is to use a lighter shade of either teal or brown -- the same color as the other objects in the room, but with white added. Lighter shades of brown include tan and beige; lighter shades of teal are turquoise and aqua. Any of these choices will flatter the other two colors.
White Goes with Everything
Clean, bright white will make the room brighter. You also might consider whites tinted with just a few drops of one of your other colors -- cream, which is white mixed with brown, or palest aqua, which is white mixed with teal.
Dark colors on walls can paradoxically make a room seem larger, as the boundaries recede into the shadows and become blurry. So consider dark brown or teal walls. Your room might become vibrant, like a jewel, or embracing, like a cave.
Orange or peach walls would flatter the brown and complement the teal. Blue or green walls would flatter the teal and complement the brown. In these cases, the complementary color should be used in smaller quantities, as an accent; otherwise, the room will have too much contrast.