how about having a range of colours put in as highlights/lowlights? that sounds weird, but i had it done, with burgundy, red, orange, gold, blonde and yellow on my brown hair (it was reddish brown, at the time), and it looked fucking gorgeous. it also grew out well (i.e., never looked a mess), and meant i could choose which colours i favoured.
i'm trying to find a photo of something similar - watch this space...