New Delhi, July 10 -- purple and red.

a prominent place in Pierpaolo Piccioli's debut Haute Couture collection for Balenciaga, unveiled during Paris Couture Week. Piccioli sent a model down the runway in low-slung, ultra-wide tomato-red trousers paired with a lilac blusher adorned with three-dimensional floral tulle, finishing the look with electric purple leather opera-length gloves, a signature move from his Valentino days repurposed for a new house.

That the pairing works at all might seem counterintuitive. Red and purple occupy neighboring territory on the color wheel, which means they sit close enough to harmonize but far enough apart to generate visual friction. The effect is simultaneously complementary and charged. Color theoris...