It is completely personal choice, however I feel for all C8 owners, as it is virtually impossible to "try - before you buy" - that is to see the grey spectra wheels on a car that is the color of one you wish to purchase. To be honest, if you'd have asked me 5 years ago about Corvette wheels, I would have said they had to be chrome... Having said that, for my C7, in Watkins Glen grey, the black wheels give it a Stealth Bomber look I quite enjoy.
Again... personal choice, but do try to see the wheels on an actual car that is the color you will be going with - first.