Didn't you know? It'$ like everything el$e. It's not necessarily the prime consideration, with aircraft, but white does reflect heat and an aircraft on the ground for hours on end in most climates quickly become ovens inside if not cooled down, a la your car, right? Cooling uses fuel. Fuel costs money. I don't know what the savings are on aircraft, but by painting refrigerated ships white the owners save about 10% in costs of refrigeration. That can add up to a lot of $$$ if you own a lot of ships. Or airplanes.
Anyway 747-600X, I like white. Just take a look at those Air Canada beauties, those 747s,...........fabulous. Regards, Peter.