Well, I'm getting good at painting the lozenge....I had to redo it a couple of times, then I compared the colours to the Datafile and W&W lozenge I have and the colours were totally wrong! Not sure where the lilac and brown came from, but from what I can see the 4 colour was light and dark green, dull blue, and "dark blond" so...I repainted it all again! I must admit I'm much happier now even though the light green is a little too bright.
The dull blue is RLM 24 Dunkelblau and the dark blond is Afrika Grunbraun, both Modelmaster colours. They are an almost perfect match to the W&W decals - it sort of makes sense that colours that already existed would be used 20 years later instead of remixing them, so maybe there are other matches in the RLM series for WWI colours....

I also painted and oversprayed the fuselage underside while I was doing it. I may have gone a little too much on the blue overspray but I like the way it looks, so it'll stay.
Next step - not sure yet...I've sprayed the wings white but I'm not sure whether I should respray the upper surfaces in a buff or light tan colour as the W&W decals are so transparent......views from those who've used them would be welcome! Then a gloss coat, drill the rigging holes and add some decals......
Oh, and does anyone know what the rudder colour was for Flieger Abteilung (A) 226? Looking at the pic in the Datafile it is one solid, light colour. Not white as there is plenty of contrast between it and the white of the cross. I'm thinking maybe yellow or light blue?
Ian