Oleg, I too, flew over England this year and Furbs' shot is an accurate representation of the colours of the English landscape. I am not trying to be rude, but have you flown over England? I think, perhaps, we may be able to judge the best. Obviously as you say a camera won't give a 100% accurate representation, but from experience I think those of us who live in the country can give a good idea of how it looked.
The colours currently shown for SoW suggest a spring-look, where the fields are quite a lush green. In the summer of 1940, it was one of the hottest summers' on record, and the fields would have had a burnished look.
I do understand your theories of colour though; it will differen between each PC, but this is just my observation
Winny, there weren't rape-fields in England in 1940. I know you weren't saying there are, but I'm just pointing it out. It's interesting to compare a modern-day picture with one from 1940.