I would say put a sticker over it or contact your local BMW dealer and see what bodyshop they use and go through that route.
I work for a BMW car dealer and we have our own bodyshop and they can mix any colour that is within the BMW range, they will be doing work for me on my K1200rs in the winter.
if you had an Aston Martin where would you take it for repair or paint repair, jo bloggs or a recognised Aston Martin franchised dealer.
Even Aston Martin where I worked for some 15 years before i joined BMW 5 years ago cringed if owners phone up the yellow pages just to save money on a repair,
If you go through a BMW dealer your repair will be covered by a paint and materials warranty for several years, jo bloggs will not offer that service.
You might save some dosh but it might be a substandard repair.