I just had my hair coloured for the first time, only wanting to cover the silver strands and match my original shade of brunette. They've made it way too dark though! It's almost black and really doesn't work with my skin tone, and it's just not 'me' any more. Next time it needs doing can I ask for it a couple of shades lighter and that can just be applied over the top or would they have to do stuff with harsh chemicals to remove this one first?