Personally I say go with blue on your black rims but make sure the ones you get aren't too dark a blue that its hard to tell if they're blue or black (like telling the difference between navy blue and black socks). In the end make your decision based on what you think looks good.
The thread has lots of close up pics on MANY different wheels with many different brands of lug nuts. There's a few cars with black rims in it too. Good luck with your decision dude and don't forget about taking new pics when you put the new ones on!