https://skyrimphotos.shutterfly.com/pictures/9

As you can see, the same ground texture is used on both the top of the wall and on the ground below but they look quite different. The ground one has a yellowish tinge to it while the one on the wall is brighter. I've been fooling around in NIFSkope for a while now but can't figure out what is causing this.

Anyone able to help me out on this?