I believe the haze colour can also be dictated by the sky textures.
When I was using the FS Sky World 2004 freeware addon (it's like REX), I choose some cool dusk and dawn sky textures which produced a nice orange-ish color in the evening.
Here is how it looked like:
By day:

By evening (with a redish tint):

Other evening (with yellowish tint):

As you can see, the color of the sun light and the haze/fog was impacted by the new sun color, and all of this was done through the sky textures set I had installed
