Remember,BOB was fought during the summer months,by all accounts it was quite a hot summer so I think COD is pretty accurate.You would'nt expext it to all look too green,the sun would've bleached the fields to a fair extent.

I don't know myself but didn't pilots of that era stay away from flying in bad weather?
If so, then if you had your rain in a mission noone would be flying. :-D