[melsharkskin]

I feel as though I'm going to embarrass myself by asking a question here that is common knowledge to everyone else, but which I haven't yet been let in on, to wit: Photos from the period show a/c tires, just like period auto tires, in many cases to be a light gray rubber, almost white in some cases, though I imagine that has to do with peculiarities of the films of the time exaggerating the light color of the rubber.

I seem to have read that the synthetic rubber of the time had a lower carbon content than modern synthetics such as our car tires and a/c tires, giving it a lighter color. I see that the colors of tires vary greatly among the countries of the combatants, and from plane to plane. Is there a good match for the light gray I see so often in the photographs? Generally, I use RLM schwarzgrau for my tires just as I do for WW II tires, but I'd like to use something more accurate. Can anyone give me a brief discourse on tires of the Great War?
Many thanks,
TOM