I just did mine all in silver, aluminum colour actually, I think it looks clean.
was also considering the blue to match strut brace, but it needs alot of polished stuff to make the blue work whereas silver goes well with black.
Im still considering doing everything in black as well, it looks pretty mean with a grey car.
I did a few things with wrinkle black initially, can be hard to get right especially on curvy stuff, my fornt cover came up ok in it but i tried painting my cooler pipe with it and it was a disaster, just couldnt get an even wrinkle..I gave up on it in the end and sanded it back, it makes a great undercoat
Im thinking i might do the crossover pipe silver too waddayarekn?