Tried your first suggestion last night on a few miniatures and it does look a bit dark but i like it
and will give your other other suggestion a go when i get the paint at the weekend.
There seems to be a fair amount of variety in the uniforms in the reconstruction illustrations that i have found and imagine uniforms would have soon faded or gone darker whilst on campaign through the humidity, heat and day to day wear.
A great uncle on my Mother's side of the family fought in Burma and he used to tell us tales of the lighter side of being in Burma but he never went into any real detail about his combat experience but from family accounts he did see a fair amount of it but kept that to himself. This force i am putting together as a tribute to him and his mates who felt that the public had more or less ignored their war in Burma and didnt really want to know when they got back home.