The charcoal color is sometimes called argent. Look at the color on some GM truck grilles mid 90's. Usually on the work trucks. I use a PPG mix that uses a reactive reducer. Sorry I don't have a code. Dave
Plasti-Kote # 8115. This is a Cdn. number, the US # is slightly different. Believe this is a Ford colour.
Eastwood sells an Argent Gray Wheel paint that should be the correct color. That is what I plan on using on my 71 grill. BUt beware as it is a lacquer and don't use it over an enamel or it will lift. Lacquer is best for plastic anyway as it is fast drying and won't attack the plastic. This is how GM painted plastic.