Hi Jeff, what i should have said is the afic see at the moment the closest to charcoal is in the cavities of the gt350 (1966) Magnums. I was just browsing trying to find a wheel where they might of got the colour charcoal from. of course the magnums are black pockets, but up very close they appear to verge on very dark 'charcoal' grey. page 76 of the Definitive Shelby Mustang Guide 1965-1970 by Greg Kolasa has a couple of close up pics and they kinda look dark charcoal (not unlike some pics of S Drakes 1965 SS wheels i see, they are a tad lighter perhaps (also up close in person many repo 1965 SS look very dark grey, not far from black imo). from a few feet away against the contrast of the spoke the 66 magnums look black obviously.
the Gray Gold reference is as it is written in my original parts book printed in 65 (they even made the spelling curiosity of spelling Grey both ways, as i wrote it), it is repeated the same way in later MOC and the last version, without the spelling difference though.
of course it doesnt say how much grey or how much gold is used in the mix but it certainly doesnt say charcoal or dark grey or just grey. i might guess from seeing how some old rims have been restored (they used a different colour underneath which affects the finished colour) that perhaps a coat of gold goes on then a coat of grey, or the other way around. however that is just a passing thought on my account, it may well be one coat of grey and gold mixed together. but surely if ford mention the change from Grey, to Gray Gold, then surely their must be some gold aspect to it