Yep- there is darkness on that fuselage. When I did that cover, I was told to make it green and gray. I had really nice, large copies of the photos and of the four that showed this airplane, they DO all SEEM to show an overall darker cast. BUT- gray and green I was told. I don't believe, however, that red was one of the colors involved, at least not the same shade as the regular red Jasta 5 tail striping. I have a very large, nice version of the photo you posted and the red striping is pretty distinct. I have no real idea what the true colors may have been. Maybe a darker gray, maybe a reddish stain.....
Robert Karr
spiralling into oblivion:
http://karrart.com/karrart/index.htm