We've seen a few colors come and go over the last few seasons: chocolate brown had a big moment last year, baby pink the previous, even butter yellow had it's time in the sun. Each felt elevated, mature, even, and workable into almost any wardrobe. Turquoise is different.

Much like the Devil Wears Prada tracked the downstream trajectory of cerulean, turquoise didn't come out of the blue. It was...