I was trawling the internet to see what colout I need to paint my Russian tanks and troops and came across this site. http://www3.telus.net/Ritterkrieg/colors.htm
It provides the Humbrol paint reference (not much use to me) but also a colour swatch so you can determine which of your paints most closely match the swatch (lots of use).
http://rkkaww2.armchairgeneral.com/galleries.htm provides a range of graphics of Russian vehicles including some colour schemes.
http://www.o5m6.de/ is Engines of the Red Army - a comprehensive guide to anything the Russians used that had a motor in it.
Anyway, I'll use these as a reference point for mine. If you're doing something similar then I hope it helps. I will add other links here as I come across them.