What settings are you using for F1 2010? That's not stock!
You're right, It's not stock. It's a lighting and effects mod which changes the direction of the sun and the contrast of the colours. Makes the game look far better I think. And the shadows are much darker as well.
mod: http://www.racedepartment.com/downloads.php?do=cat&id=89&page=2
It's called "Track lighting mod full 4v" unfortunately you have to sign up to download it, but there are plenty of mods to check out on that site.