Necrons are one of those "do what you want" armies, they can be painted a lot of different ways and as long as you paint them well they'll look good.
You can check out my 'cron which I posted in another thread...
Personally I like more "exotic" schemes on Necrons rather than the old silver/bronze/gold/etc colours. I've seen some really good 'crons that were bone with black details, but the black was edge highlighted with red and orange (I believe it was 3 layers of highlights, a dark red, a blood red and then something like a blazing orange). They really looked "wow" when you saw them on the table.
So just pick some colours you think look nice together, then decide how you want to paint those colours (metallics, flat colours, edge highlighting, softer highlights, etc) and just get stuck in and stick with it until the army is done.