Hi guys, thanks for the feedback!
Yeah, I actually purposely desaturated the yellows in the whole scene to give it a cooler/fresher feel. It's supposed to be a bright, but cold day so I felt the fog was still apt for the situation. I do agree however that the transition from fog to no fog is too much of a contrast and it could've probably been thinned out a little. Before I reduced the yellows I felt that the whole thing felt too humid and green in comparison to the bright blue sky and it just looked a little wrong together. I didn't want to go overboard with the post processing either really so tried to mute things a bit. Anyways if anyone's interested there's a load of dev shots here of it in various stages of build/lighting so you can see how it was previously --> http://%7boption%7d
Also there's a vid here so you can see it running if you can't be bothered to dl it
http://%7Boption%7D