Oh Jeeze
well, I don't wanna tell you to keep bleaching it because it's actually pretty harmful to the hair, but often times, if you've bleached it enough it'll just start growing that way because so much pigment is being constantly stripped from the hair. Anyways, sometimes you can buy that spray on stuff that's just so temporary it's unreal. It'd probably be safer, but to my knowledge, blue bleach is the most permanent option at the moment.