A bit late now, but for the archives...
If you download PET (unofficial but everyone has it) or the official Porsche released parts list PDF files from porsche.com, and look up your wheel part numbers, at the end of the part number is normally a 3 digit code, that code is the paint code which you can then buy or have mixed up from paint factors.
The same is true of centre caps, if you want to match the wheels to your chosen centre caps, then the paint code is listed as 3 digits at the end of the centre cap part number.
