To answer your question about color during and right after WW 2. All of the engines both diesel and gas were painted black with white lettering. This information is direct from the Army Spec regarding painting and lettering of railway equipment. This is a Army Transportation Corp document that we are using to paint al letter a gas mechanical we own. In later years engines that were used at various ammunition plants may have been painted yellow but that was not used during the war years. Our engine after it was used at an Army Air Corp base was transfered to a Naval Air Station and at some point was painted blue but that was a number of years after the war. I will be glad to share this document with any of you. Send me your address either email or snail mail and I will get you a copy of it.
John Deck
Great Plains Transportation Museum
Wichita Kansas