Voss's F1 (103/17) was doped turquoise overall then at the factory the upper surfaces (wings tail and fuselage including sides) were painted with a streaked olive finish. The argument about Voss's aircraft is was the cowling yellow or olive. Of course don't forget the white
eyebrows /Moustache painted white on the front of the cowling. There are published photos of this aircraft. One reference is the second set of photos in Peter Kilduffs book Ritchofen beyond the legend of the Red Baron. Another reference is Von Ritchofens Flying Circus. Pages 32 and 33 (3 photos very close-up in fact) This book was published by Albatros publications and written by greg VanWyngarden.