While purple shampoo is best for those with blond hair who want to maintain their platinum or buttery highlights, blue shampoo is utilized for the opposite side of the spectrum: brunettes! As Redken explains, blue shampoo works for brunettes who want to neutralize red or orange tones in their hair. Whether coming after a balayage treatment or all-over hair color, a blue shampoo will work to counteract brassiness, and will have just the pigment to be effective for darker hair.

New York colorist Calla Dawn told Byrdie that "using a blue shampoo is a great way to keep [brunette] hair looking cooler-toned between appointments," while those with blond 'dos will surely benefit from purple treatments. While both kinds of shampoos will maintain hair color beautifully and effectively, BeautyHeaven warns that using the wrong one might lead to a full-blown catastrophe.

The outlet explains that blue shampoos are heavily pigmented and may stain more than purple, so it is recommended to use it with caution. Using gloves will prevent staining your hands, and making sure your hair is dark enough to use blue shampoo will be best. Whether going the purple or blue route, each of these toning shampoos will make sure your hair color lasts longer, even with a few extra beach and pool trips in between!