I've had to paint my allies a lighter olive drab for this very reason. I thought it was just my red-green colour blindness but in poor light my friends can't tell the difference between the axis and allies either. Judging by pictures on this site other releases of Memoir don't suffer so badly from this problem.
Huh, that's a thought. I'm in the middle of painting my Battlelore sets now, but maybe a quick spray with army painter primer would suffice to distinguish the colors better. I probably do have the first printing, too.