Thanks for your replies.
Cletis: our truck is currently two tone green. According to
Old GMC Trucks Ditzler chips and the Old GMC
Spec sheets the colors are (lower) Jungle Green and (upper) Huron Green. To match spec I would hit the rims with Neptune Green.
Red: Thanks for your insight. I may have adapt if I want to go powder on the wheels or switch to paint on the wheel rims if I want true stock hues.