Ooooowwweeee, cutout and knee dent color is a tough one! Based on the VeeDub dark gray you're using, I immediately thought "black." But, then me thinked, keep them the same color and pinstripe around them in either black or a lighter gray for a subtle way to offset them. Or, if you wanna go nuts, do them in either a brake-caliper red or your shock-spring yellow to make them POP!