Unless you were the bride or a man in a crisp white dress shirt, wearing white — especially a white dress — to a wedding was once a serious breach of etiquette. Unless you get explicit permission from the couple before the big day, it’s still not advisable to wear a white gown or even a white cocktail dress to the big day. But you can wear a white blouse, skirt or jacket, assuming it’s being paired with a bright pop of color or bold print.