I've also been progressing (slowly) with my painting for 8th Army, plus I've also been pondering my Wars of the Roses figures - I need to get them finished up, as at present only around half are painted beyond a very simple base-coat.
From my progress spraying the 8th Army a light desert-brown, I found myself pondering the same option for the Arrayed Levy troops in Wars of the Roses. Sounds mad, but not entirely. From internet forums discussing WotR armies, the general conclusion on colours appears to be:
1: Nobody really knows anything.
2: Undyed, bleached linen was likely to be widespread, meaning a variety of browns & beige in varying tones pretty much anywhere outside the liveried retinues.
Makes sense I suppose, as why would you - as a poor peasant of the day - feel like getting dressed up in your best clothes to go to a battle, unless you were really interested in leaving a good-looking corpse behind? Hm. Still, I suppose there's nothing else for it - I'm just going to hav eto launch myself into a full-scale painting effort yet again. Hopefully a few intense sessions of effort should see me power through a lot, rather than my usual style of numerous, snail's-pace progress sessions in spare half-hours snatched here and there!