Personally I am not keen on either of them, but if you like them then go for it. Mine is Silverstone II but I like Interlagos Blue too, Black also looks good. Not sure about White, works in Florida..
silverstone 2 with black! Thats what I bought 2 weeks ago anyway! seriously, forget the colour and look at the history/condition and BMW warranty! I really wanted an interlagos blue one, but the condition of the silverstone one I bought swayed me!
I love Sepang Bronze, especially with shadow chrome wheels. Just a shame many of the first owners seem to pick that nasty white leather at the same time.