What Causes Brassy Hair? "Brassy hair is caused by color that lacks a grounding tone, such as brown or beige," says ...

If you’re going from blonde back to black, you really need to leave the dark dye on for a long time. Otherwise, when it ...

"It neutralizes the brassy tones that occur when lightened ... While blue shampoo is recommended for color-treated brown hair, natural brunettes can also benefit from its unique formula.