I have the BMW R75 with sidecar, so I am guessing you are talking about the fig who is standing?
His helmet should not be camo. There is no mold on it that indicates the cloth cover that they wore on there helmets.
his camo smock should be painted the following method.
Dark yellow base coat
Camo blotches with Red brown and dark green
then add the spinters with some black green.
much like this
this is a luftwaffe camo smock.