I’ve never been one for color theory, or color wheels, or undertone rules, or anything like that. I don’t know if my red lipstick ‘should’ be more blue or more orange. (I also don’t really care.) But what I do know, and would have never known before now, is that purple conditioner makes blonde hair blonder. Oh yes, it does.

Of all of them out there, Christophe Robin’s Shade Variation Care Nutritive Mask in Baby Blond is the Rolls Royce of purple conditioners. Davines’ Alchemic Conditioner in Silveris quite good as well. There are also purple shampoos, but I don’t really trust those, in the same way that I don’t trust self-tanning body wash (but in a different way than my distrust of Snapchat). Monsieur Robin is an elegant French colorist who works out of the Meurice Hotel in Frahhhnce, counts Catherine Deneuve as a longtime client, and creates tiny batches of supremely gentle hair care products that are endearingly difficult to obtain Stateside. In lieu of conditioner, I work a big scoop of his bright violet mask through freshly shampoo-d hair during my twice-weekly washing. I shave, I clean my face, I sing Drunk in Love at the top of my lungs, and then I rinse.

One would think, staring at the purple cream, that no such thing should go near platinum hair. On the contrary! The more purple the better. Leave on for five minutes or even ten, and any brassy tones that have developed from…life? Saltwater? New York City air? are neutralized. The only thing keeping your hair from looking day-of-bleaching-and-toning-good are your 6 weeks of root. Hey! Nobody said being platinum was easy.

—Emily Weiss