To avoid haircolor blunders when trying to go back to a darker color avoid products with ammonia in them. Many haircolor products warn against using them over previously lightened hair. Color by Robert Craig is the perfect product to return your hair to it's natural color. It contains NO ammonia or peroxide that can cause hair to become over porous and grab or turn grey or green. We do suggest using a shade or two lighter than what you want to achieve because it is always easier to go a little darker. Always do a strand test before committing to any product. If you are blonde and wish to go brown, then you need to do it in two steps. First use Robert's Golden Blonde. Apply roots to ends for 35 minutes, rinse, shampoo and dry the hair. Then apply the brown shade shade of your choice in Robert's haircolor. Process for 35 minutes, rinse, shampoo, condition and style.