Lothar was recuperating from his March crash injuries until sometime in late July or August. All the photos I have seen of his return show him getting ready to fly
Aloys Heldmann's airplane, 244/18. The markings of this plane are well documented - AH initials in cursive on top wing, Fokker streaked fabric on fuselage, lozenge fabric on wings, checkerboard tail, monochrome nose panels probably Jasta 10 yellow.
I don't know when or even if he actually flew a Fokker with any of his own chosen colors. Apparently one was painted up for him, red with a yellow tail like his triplane, but photo captions recite that it was actually flown by Hermann Göring instead.