Our FedEx planes have bare wings too for the standard reasons. Our Airbus wings are painted to Airbus specs and not in FedEx colors. As for the corrosion, I con't have to work on that thankfully as I work in a back shop. One of the reasons we changed our color schemes in our last paint scheme makeover was to use more white than purple/orange. Less pigment in the paint which again saves weight and the white lasts better in the sun.