i had the same problem as you.. got a 2nd hand saw which needed a bit of a tidy up cosmetically. Read here about the Stihl grey paint and marched to my dealer with the item number- problem was here in Northern ireland we only have one main stihl dealer (lots of smaller satellite dealers who go through the one main dealer) and although theyre nice to chat to.. theyre not that good when it comes to requests for more unusual items.. like paint, roller chain catcher or dp mufflers! The closest he could go was to point me in the direction of the stihl brand tree marking aerosols!!
Anyway i was back on this site searching old posts and some GENIUS suggested "Ford tractor gray" paint. i had no problem getting it and it was a really good match. (i must look back now and find out who it was and rep him now i know how to do that!
regards andrew