Supposedly, the gray was to conceal the vehicles in the shadows beneath tree cover during build-ups. Once the armored divisions were on the move, concealment was thought not to be an issue, as they had air superiority at the start of the war. Dark gray was very dark when fresh, but could appear dramatically lighter with only a slight coating of dust. However, the standard paint was so dark, it was nearly indistinguishable from the dark gray rubber on the road wheels. There are a few b&w factory photos of Tigers which were delivered in a lighter color in 1942, which may have been the medium gray shade used on railroad engines. The Henschel factory in Kassel also build locomotives, and this color may have been substituted when the regulation gray was in short supply. GPO