I do wonder if the US followed the British practice of a Kahki Brown shade. But I also wonder if at a later date they would have followed inter war US practice of a semi gloss Olive Drab colour?
Would this have applied to M1917's and the Ford 3 tonners as well?
Very hard to find any decent reference out there on the subject.
Just stumbled across this thread; the original poster has not been on the site for six months, but if anyone else is interested, I recently came across an article on US colourschemes on the Military Modelling website. The implications of the article,as far as I recall, are such that US Mk VIIIs would have been a dark olive drab, not necessarily semi-gloss, but only early examples would be likely to have been matt. So, yes, olive drab, probably semi-gloss, and both darker and browner than the olive green in taz's Fort Meade pic above.