I like the dark gray. It is neutral which goes well with any paint color, it is not a 'black hole' of contrast which the black would be, it is not overly bright overwhelming the car as white would be, and while the gold may authentic for some race wheels, it is still a color which may not be complimentary to the car colors and would draw attention away from that.
First, thanks to all of you for the replies.
The rims are Australian Superlite from TransAm, looks like a Minilite but not quite. Made in China of course, like everything else but good quality at a decent price. Lots of the guys who race historic and a bit more modern use those wheels.