My "go to" Reference on the DR.1 is Paul Leaman's excellent book on the subject. It is full of very clear photos and Color Profiles by Harry Dempsey. Most photos of the aircraft with the factory "striping" finish have the bottom color wrapping onto the upper surfaces of the tail plane in a thin band, and the same on the fuselage sides which are illustrated on the profiles. I'd say you're correct about the blue stretching onto the top streaked color.
Cheers,
Lance