Bye bye, a hair mask that brightens, hydrates, and softens yellow hues. It is designed to reduce the brassiness of color-treated blonde- grey and silver hair tones. It also balances out yellow hues on the color wheel. Basic color theory suggests that purple hues cancel out yellow hues because they are positioned on the opposite side of the color wheel. When applied to yellow- brassy hair, Purple Mask works best. Apply to damp hair and leave it in place for 5-7 minutes.