Why is the mist in the mistwoods literally beige?

The title pretty much cover's it. In the trailer, the mist was a normal, white color like mist should be, but in the actual game its sort of a light-beige color.

 

Trailers almost always use shaders, so the fog in them won't match what you see in game. That said, I kind of like the beige – it makes Mistwood feel warmer and older instead of just "generic foggy forest". Does it look different for you at different times of day?