Des, the choice of colours by interpretation of black and white photographs alone does leave a wide area of colour choice, to be sure, but there are other factors to be taken into account both documented and circumstantial, which help to nudge us in a certain direction or other.
With the aircraft in question, one of the pieces of information which would tend to direct
me to a red/white interpretation, is the documented fact that many/some of Jasta 43's Fokker D.VIIs were passed on from Jasta 18, whose colours of red and white are well documented. Jasta 43's marking of a white tail was achieved on these machines simply by leaving this area as painted in the Jasta 18 livery and modifying the rest of the scheme by varying degrees.
Attached are some drawings I have made of Jasta 43 D.VIIs and Options 4, 5 & 6 and
possibly 2 are representative of these machines. Some of these will be appearing in future Pheon decal sets and you can rest assured that I won't be "pushing" any particular scheme without some evidence.... an approach followed even more assiduously by Wingnuts - in my experience:


In the final cut though, the choice of colours is yours - it's your model after all and what others think is neither here nor there. Whatever you choose to do, one thing is certain; it'll be a cracking model!