I guess it depends how late (cold) it is, and whether it's indoors.
A shawl/wrap/fancy sweater might be enough, or pantyhose/tights with a dress. Or pants, I guess, but that's pretty unusual.
I went to one last week outdoors and it was pretty cool (rainy), I wore a black knit sweater that suited my blouse/skirt and it was warm enough for me. It'd be tough in say, late Oct or Nov, but would anyone really have an outdoor wedding then?
edit: I assumed you were talking about the cold but maybe you meant fashion instead? In which case I have no idea other than substitute black for white?