To Slominer….
Slow news day and maybe the mishpacha is up in Monticello and you have time on your hands. A kalah can wear ANY color to her chassanah, although the minhag is obviously white (but some could argue that has become derech hagoyim so she could wear any other color, albeit tzanuah, and be OK). I’ve been at several frum weddings where chashuvah rabbonim were mesader kiddushin but where the kalah wore other light pastel colors.