it does not stay forever which is a good thing imo [SEP] atomic pink really does glow in the black light i went to disneyland and on the winnie the pooh ride my pink highlights were a glow it does not stay forever which is a good thing imo i had put way too much and after a few washes got it to where i liked it a little goes a long way and i have not even made a dent in my bottle yet i wanted the sold out cupcake color so i just mixed this with conditioner and it all worked out well