AP-42 emissions equations for tankage does have a paramenter for tank paint color.
That is why you almost see all refinery tank colors universally white.
In a tank, the white paint decreases the impact on product temperature, thusly decreasing volatilization. Same concept applies to an abode, if you can keep the inside cooler, less electricity is needed for the cooling side of HVAC. Of course the opposite is true in winter.