If you have friends with dyed blonde hair, you've probably heard them talking about how purple shampoo keeps their color from turning brassy.
Fading and brassiness isn't a struggle that's exclusive to blondes. Unnatural brunettes are also prone to developing unwanted warmth in their color. However, there hasn't been a cure-all product for those of us with brown hair looking to make our color last longer. That's where blue shampoo comes in. It's a total game-changer that fills this void for brunettes.
The easiest way to understand how both purple and blue shampoos work is to compare it to the color-wheel theory. Similar to how purple shampoo neutralizes blonde hair shades, blue shampoo follows the complimentary color theory by canceling out orange and red undertones in dyed brown hair.
"Blue shampoo works by canceling the orange/reddish undertones (the same tones that are commonly called brassy) that are part of the underlying pigments," explains Mincho Pacheco, master hairstylist and colorist at James Joseph Salon. "It neutralizes the orange by making it more deep."
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Dyed brunettes will benefit the most from using blue shampoo because their hair cuticles are expanded, but it will make virgin brown hair extra shiny because most of the pigments stay on the hair's surface.
The stylist recommends that unnatural brunettes use blue shampoo once to twice a week, and natural brunettes wash with it up to three times a week.
There are a number of blue shampoos to try. Keep scrolling for our favorites for brown hair.