I have really blonde hair, it's platinum, and although it's highlighted it looks like a block colour. I'm wanting to go from platinum to a darker blonde such as in the pic of Nicole Richie i've attatched. last time i went to the hairdressers i asked for darker blonde and she just added darker highlights. this made no impact on the platinum, and i just looked like i needed my roots doing straight away! i'm going to the salon tomorrow with what looks like terrible roots! just wondering if any of you can advise me of what i should ask for, do i need a block colour over all the platinum and then highlights? i'm lost! and i don't want the same as last time! please help!