blue-rinse
verb1
To treat or dye hair with a blue rinse.
noun, verb — 2 senses
A diluted blue hair dye used to reduce the yellowed or translucent appearance of greying hair on older women (because the ability to see the color blue decreases with age).
To treat or dye hair with a blue rinse.
Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — authors: page histories for blue rinse and blue-rinse.