It's also related to the general fact that early on in the war bright colors were possible as the Germans were on the offensive. Bright flashes of color were permissable to help identify units and coordinate on flight leaders, etc. As the war progressed they were placed more and more and more on a defensive stance where bright colors served only to bring the hunters down on them. The bright colors gave way to more camouflaged colors across all fronts, for the sake of survival. Those with bright colors were seen by the allies as leaders, aces, etc, and targeted relentlessly in some cases.