Is the “Three-Wash Rule” When Dyeing Hair a Real Thing?

If you’ve ever left a hair color appointment in fear that you hair looks a touch too artificial, you may take comfort in the concept of the “three-wash rule.” Fact for some, mythos to others, the general concept is clear: new hair dye takes time to settles in. “When we put color on our hair, it’s pigmented, and once you start washing the color transforms the structure of the natural hair,” explains celebrity hairstylist Dimitris Giannetos. “Some colors are more red, so they’re going to hold the red undertones, while some colors are more ashy. When you start washing and the dye settles, you’ll keep the tones more aligned with your natural color.” This blending is likely aided by the effects of time, too. “Depending on the color, it can look a bit more settled after a couple weeks simply because your natural has grown in a little,” says celebrity colorist Emaly Baum. “This is especially the case for highlights. It gives a little more natural depth at the root.”

Because there’s value in contrast, it’s worth noting that celebrity colorist Jenna Perry disagrees with the premise of the three-wash rule, as does Baum—but that’s not to say she doesn’t understand it. “Personally, I think that color always looks best right after it’s done—maybe I’m biased!” says Baum. “I think often, after a fresh color, you’re just not used to seeing yourself with bright highlights or no grays or even just your natural root. It can take a few days after getting your color done to really get used to seeing it in the mirror.”

Regardless of the moment you fall for your new hue, maintenance is essential. “Proper hair cleansing is important to maintain the vibrancy of your hair,” says Perry, citing the perils of hard water, which can lead to dry hair for all and brassy hair for blondes. “Harsh water can also make your color fade faster or even add a really dense yellow green hue,” says Baum. “If this is a concern I’d recommend getting a shower head filter.” Products matter, too. Perry reaches for all things Olaplex—particularly the Volumizing Blow Dry Spray and No. 7 Bonding Oil—while Christophe Robin’s Colour Shield Shampoo is Baum’s go-to for color-treated lengths. “This is a low lather shampoo that leaves your hair feeling clean but hydrated,” she says. “For conditioner I love Davines Vegetarian Miracle Conditioner—it makes hair feel soft and healthy instantly—and after the shower I always tell my clients to use a leave-in like Reverie Milk. Giannetos relies on Garnier Fructis Hair Filler Color Repair Shampoo and Conditioner for smoothness, shine, and color maintenance—and even with the potential benefits of the three-wash rule, warns against over-washing, a feat made easier with the help of Morrocanoil Dry Shampoo.

Consider the three-wash rule a loose timeline for allowing your new shade sink in rather than a hard and fast dictate. (After all, most beauty “rules” come with a caveat.) Strategic color care, however? That’s a non-negotiable.