Why are objects in the shadows being highlighted?

I’m trying to get some nice lighting in my scene but all sides that are at a certain angle are being highlighted either by the skylight or global illumination.

Here’s skylight only:

http://puu.sh/nlP7p/300adcd763.jpg

And here’s built lighting with a skylight:

http://puu.sh/nlPeq/5c3a619bca.jpg

The ground is green and it’s far below. But no matter how occluded the side is it still has a green tint and it’s bright:

http://puu.sh/nlPiF/5f99b566b5.jpg

Does anyone know how to fix this issue?

Thank you.