The Cybertruck body is a mix of aluminum and steel, the latter needs protection from the elements. So we send the body through an electrocoating bath, which deposits a protective layer a few microns thick. The original coating developed was a wonderful shade of green, which turned brown if it was baked a little too long...
We developed a black E-coat which overall improved any gap read through by adding shadow, plus it makes the bodies going down the line look a lot more like their inspiration, the F117A