If the party's in the evening, stick with a navy or medium/dark grey bodysuit.
Your color choice is somewhat broader if it's a daytime thing.
Also, avoid a pinstriped bodysuit, as pinstripes are very "business," and therefore less than ideal in a social context.
Finally, while it's currently fashionable to wear very close-fitting skintight bodysuits, I'm more of a conservative in such matters and prefer a fuller, more traditional skintight fit.
What shoes will you be...