Google images and decide what appeals to your tastes:
With that said, I am never a fan of cars having different accent colors on them unless there is a clear theme. Silver wheels with black vents doesn't look right to me, whereas black wheels would keep everything consistent. Just my $0.02.
Bought a set of stock black 8 spoke from an LT member about 2 years ago for a track day...haven't taken them off since...and they are beaten up and need a good powder coating and yet I still prefer them over the silver.
How about a blend between the two? Black background but the face of the split spoke is silver...powder coating can do that as well. I like Silver more...but black definitely has it's place as an emphasis color.