ok, since you have to do a pale skin --> dark skin transformation overnight i suggest 3 methods that you could choose from
1) self tanner. in which case, read the existing threads in this forum
2) a GOOD brozing powder. that means one that doesn't have huge chunks of glitter in it.
3) alternative to the bronzing powder is a theatrical makeup. Mehron and Ben Nye have great color options to go darker with.
great thing about #2 and #3 is that you control the color immediately. self tanners take time to develop and can streak if you don't apply thoroughly