The 100 Foot General has a very useful post on colors that should appear in the clothing of a Dark Ages army: Dark Ages Color Palette.
Painting Guides
Painting Japanese World War II Soldiers
As I said in a recent post, I think that WWII in the Pacific Theatre is a deserving, if underappreciated, period. (I’m regretting selling my Japanese and Marines a few years back). Here’s some advice on painting the Japanese.