Scott;
Hi!
Probably, as you are talking late 1942+ for the Panzer III-N in north Africa, you should be using the later-version 1942+ general two-color "regulation North Africa scheme" of a base-coat in Braun RAL 8020, with a feathered-edge sprayed-on camo coat of GRAU 7027 - usually supposed to be about 1/3 of the total vehicle area in the grau (gray).
This scheme was usually applied at the shipping depot in Italy, or even at the vehicle assembly plant, so this would have been a neatly-done "factory paint job". As an aside, some of the vehicles painted in this scheme ended up going to southern Russia in mid-1943, as they were not ready to ship to Tunisia before the DAK campaign ended.
I would suggest looking around on this or other model sites to see what paints will best work to fit these colors... While I plan on doing a -III in this scheme myself, I have not yet identified the "best" paints to use... I vaguely favor ModelMaster enamels and Tamiya acryls - Tamiya probably does not make a close match, but I think that ModelMaster may make something close to one or maybe both RAL colors. Vallejo probably offers some close colors, too.
Cheers!
Bob