For Brown I have been using Halfords Red matt undercoat more of a red oxide. For green I have used Ford Laurel Green. There are always queries about colours here, many options have been suggested but colour is not such a precise thing as we would imagine as LGB Brown wagons and coaches over the years will show. On the real thing colours fade over time with weather plus dirt, mixes are not always precise at the factory on the real thing either. So I do not get that worried and feel a few varieties of shades actually represents the real thing nicely.