The darkness has nothing to do with it bro. If the heat shield is black it will basically hold on to any heat radiated against it; Causing it to heat up a bit, and thus the intake temp to be slightly higher. If however the shield is white, whatever heat gets radiated to the shield has a better chance of being reflected to the engine bay and not the inside of the intake itself. If you want, do a search for ??back body? or something to that effect. White may not look as nice but, it is the best solution. Insolating the hell out of it should let you pick any color you would like.
-2 cents
