This stuff is a life saver when coloring your hair! It's even great on natural hair or highlights that get brassy from the sun or just fade over time. I keep a box on hand (now that I am a “blonde”) to tone down any gold/red tones that are “too much”. You can leave this stuff on for way longer than the instructed 10 minutes (GASP!! LOL) to REALLY fix brassy hair from a bad dye job. Same stuff they use in the salon for much much less. Love it. L'OréalColorist Secrets Brass Banisher