I'd say anything of a medium tone intensity in a colour that complements the wood. Too pale and it will jump out at you, too dark and it will be too sombre, unless you plan to add rugs to break the dark wood. I'd probably go with a khaki beige, dark driftwood or mid-brown in the naturals, or terracotta red, mid slate blue or even sage green if you want to make a statement... In leather, of course.