When Valentino unveiled his groundbreaking all-white Collection Blanche back in 1968, he was heralded as the sheik of chic. Ever since, designers have followed his lead by openly defying the old sartorial prohibition against wearing white after Labor Day. (This season's rebellion comes in the form of Valextra's knee-high leather boots, Balenciaga's fur-trimmed wool coat, and Goyard's achromatic luggage.) Watchmakers are staging their own uprising with the recent introduction of chronographs and tourbillions anchored by ivory bands made of ceramic at Chanel, shagreen at De Grisogono, and something called tropical composite—which looks and feels a lot like rubber—at Patek Philippe. How to carry off a stark white watch in the dark days of winter? We thought it looked perfect on the woman we spotted front row at the Proenza Schouler show: paired with an alabaster mink vest, a black cashmere sweater, and jeans. From top: Hermès, $1,750; 800-441-4488. Patek Philippe, $9,600; 212-218-1240. Bulgari, $3,300; 800-285-4274. Jaeger-LeCoultre, $4,500; 800-552-8463. Chanel, $3,450; 800-550-0005. De Grisogono, $175,000; 212-744-7160.