I seem to recollect that you cannot order a car in Individual until sometime after it has been launched. Usually that means 1 year or so. By all means ask, but BMW in the UK usually delay the availability of the Individual programme and it's not available straightaway.
If you can choose Moonstone I can highly recommend it. A friend of mine had his M5 in Moonstone and it's like a mixture of white and silver - very special looking.