it's called Alpina White code 300. There are three versions if I recall, 300-1, 300-2, 300-3. 300-1 is for the E30, 300-2 is for E36 while 300-3 is for E46. Between the versions, 3 is the "whitest" and I think the E90 uses a 300-3. The major difference, I was told, was in the base coat colour used.