i had my hair coloured about a year ago, and now my roots are really showing through but i dont want it dyed again. after searching on google, i came across i forum, in which someone said, a product called "henna" conditioner, can remove colour from hair(it works by applying mass amounts of the conditioner for long periods of time, then washing off). im just wondering, will this still work if iv had the dye in for so long?