pastured: not a chance that lemon juice is going to work on synthetic hair colors. if you have dyed your hair 2x in the past four months, it is not going to penetrate the color deeply enough and you will get streaky, patchy results. why would you put an acid on your hair? or bleach? bleach is awful and lightening hair is difficult as FUCK so i always advise people: CHOOSE CAREFULLY. if you don't want dark hair, don't dye your hair dark. and if you want light hair, bleach VIRGIN hair.