Here's a GPW-era painting of an Il-2 by an artist named S. Tsvetkov, in the late-war AMT-11/-12/-7 scheme:
I think this is interesting, not only for historical reasons, but also because it offers a sample of these colours
as matched by the eye and palette of a trained, professional artist, who was actually there to see these colours himself! (or herself, possibly...)
The original web page is here; it contains some very inspiring and thought-provoking works of art:
http://www.allworldwars.com/Soviet%20War%20Paintings.html#10Link to page 2 at the bottom of that page.
John