I don't know if the rules are clearly stated anymore. I heard that white is right anytime just make sure you are fashionably dressed. The maxi dress is back in but so is the shorter skirt. Wear colors that work well together, different colors at the same time are ok, but make sure they compliment each other. There is one rule that is constant: always have a little black dress in your closet. It can be dress up or down as needed.