skip the oem style lugnuts and screw on plastic caps and get some chrome acorn lugnuts from yoru favorite parts store. for about $20, you get all 20 nuts.
personally, i think it looks better with the 5 chrome lug nuts contrasted against the black wheel. a GN is black enough as it is, and the chrome nuts make a nice companion to the polished lip of the GTA wheel. plus, you don't need to worry about the plastic covers fading to gray in the sun and/or getting lost.