Color on post WWI US aircraft - and other details

Many years ago I did a b&w painting from a b&w image in a magazine of a Barling Bomber (WITTEMAN-LEWIS_XNBL-1_USAF). I have never been able to find the exact image that I painted from but have found others. All the while, I wonder what the color scheme is on the plane. Particularly the 3 stripes on the tail (see image of flying Barling Bomber). Perhaps the colors were the same as on the Martin MB-2 (2nd image).

The second question, more universal to many early aircraft - The wheels on the Barling Bomber were spoked with wire (kinda like a bicycle tire) but then covered with something to reduce drag I suppose. In the photos of early planes with such coverings on the wheels there appears to be a round hole near the rim (image of Barling Bomber wheels). What is the round hole for? Is it merely to gain access to the tire valve? Or does it serve another purpose?

-- Jeff in Arkansas

(p.s. with my line of questioning you can see that I know very little about this.)

[davecww1]

Yes, I think the blue/white/red rudder stripes would be common on all US aircraft in the 1920's, with overall olive drab (undersides as well). The holes in the wheel covers were as you stated to allow access to the tire tube air valve!
Dave