While fair-haired folks often deal with a yellowing effect, brunettes often see an orangey hue. Blue shampoos are one way to combat this—they neutralize the coppery color by adding a cool-toned finish. Just bear in mind that "blue" is somewhat subjective. So while you'll find plenty of undeniably cobalt options, many lean toward indigo and even violet. Made specifically for lightened brunette hair, this sulfate-free shampoo deposits blue-violet pigments to reduce brassiness and counteract unwanted warm tones. Blue vs. Purple: There are lots of blue and purple shampoos on the market. And while they achieve roughly the same outcome, blue is generally intended for brunettes, and purple is for blondes. However, some blue washes lean more toward indigo (and sometimes violet) than classic blue. Boasting a blend of "blue-violet pigments," Matrix Total Results Brass Off Color Depositing Blue Shampoo contains a bit of both. In any case, you can pretty much count on a reduction in brassiness and an overall cooler-toned finish.

Theresa Holland has been contributing to Byrdie since 2020, covering wellness, makeup, skincare, and haircare. For this story, she interviewed two stylists for product recommendations and insight into the science of color-depositing hair washes. Having tried a handful of blue/purple shampoos in the past, she's particularly fond of Fanola and Kevin Murphy. You can read more stories by Theresa on MyDomaine and The Spruce. Frequency of Use: Most blue shampoos are intended to be used two or three times a week, which is the case with Not Your Mother's Triple Threat Brunette Blue Treatment Shampoo, though weekly use is often plenty. Be sure to read the directions carefully to avoid overusing it, as the blue pigments could leave your hair with a purple tint. "Sometimes purple or blue toning shampoos can over-tone and cause the hair to look dingy," adds celebrity hair colorist Guy Tang. While there are many standout blue 'poos on the market, Matrix Brass Off shines above the rest. Formulated specifically for lightened brunette hair, this sulfate-free hair wash deposits blue-violet pigments to minimize brassiness. In other words, it creates a stunning cool-toned finish that brings out the intended effect of your color-treated hair. The vanilla-rose scent doesn't hurt either.Shelly Aguirreof Chicago'sMaxine Salonis a professional stylist with 12 years of experience teaching at salons and tradeshows. Overall, our favorite blue shampoo is Matrix Total Results Brass Off Color Depositing Blue Shampoo. We love that it's formulated specifically for lightened brunette hair and that the sulfate-free blend uses blue-violet pigments to provide a brilliant cool-toned finish with no brassiness in sight. Having said that, Not Your Mother's Triple Threat Brunette Blue Treatment Shampoo is an excellent choice for those on a budget but still want to tweak the orange out of their warm brown highlights. Apply blue shampoo to wet hair in the shower. Lather it around, focusing on the color-treated sections, and allow it to sit for three to five minutes. Then rinse it out and use a conditioner like you normally would. Some blue shampoos call for using gloves to avoid getting the color on your skin, but most will wash clean from your hands when you rinse your hair.