The punch bowl Or a blazer and grey flannels. I have a red vest that I wear to such ocaissions, too. With lots of dark cloting I tend to wear red socks at this time of year. But then, I don't take myself seriously at all.
Alexis's recommended outfit is to cool, I think, if you are over 30 or not a cool cat naturally. I could never pull off the black/black look. But I would go with a dark suit and cool shirt (not plain white) without tie and black shoes. If you have a checked spread collar shirt with a charcoal suit maybe?