"He has strong views about which colors work with which shoe. If I were wearing his aqua-colored, glitter dégradé party shoes, for example, he would advise nails painted with his pale-turquoise Batignolles. With fall’s Luciana platform, designed with a latticework of patent leather across the toes, he recommends Whatever, a navy. For the Pense à Moi shoe, a fantastic fuchsia-and-orange satin concoction, he says wearing the dark-violet Lova would look very YSL. You can always, he says, match your nail color to a stone in a ring, or the setting. With gold settings, he warns, never wear crimson nails, and with emeralds, a pale pink like Madame est Nue would be chic."