981 GTS Carerra S Wheels - Change to Satin Black

[Spenny64]

This has probably been covered elsewhere, but I sure as h*ll can't find it.
I'm trying to find out what the OEM colour reference is for the Porsche satin black wheels.
Mine (2015 981 GTS Guards Red) has the standard satin alloy colour and I want to get them powder coated Porsche satin black.
It was an option code '344' on the original 'Porsche 981 GTS Option Prices'.
I've searched the tinterweb to no avail so far.

Any advise much appreciated.