This is unbelievable! In my game, always as dominant colors survived red/blue/purple…no green. I have been frustrated for hours beacuse of this. And now, here is what was going on.

XNA color system
Color.Red = (255,0,0)
Color.Blue =(0,0,255)
…and behold
Color.Green=(0,128,0) :O

this was causing serious handicap for green…unbelieable!