of course it is possible to lighten brown hair to blonde. HOWEVER! When the
hair has been dyed brown, black, violet or red.... beware of what lurks beneath as
the hair may be extremely stained with color.. inside and out. Avoid regret; by
conducting a strand test. Wrap several strands in lightener, and observe after 20 minutes.
If the hair has held on to too much depth. adjust your expectations.