Creating a Material Landscape I used both Layerblend and the Slopemask in order to be able to paint any layer I like but also automatically add for example the Rock texture on cliff sides.
With this Example Image of the issue what you see is on the left the dirt layer applied automatically using the Slopemask and the MatLayerBlend_Standard and next to it the same material function being applied using the LayerBlend and painting it on the landscape. As you see the painted texture is much darker and I dont understand why!
Here is my Landscape Material image and how the LayerBlend was setup, it is worth noting that my Rocky_Grass texture also is darker than the actual texture output but it is harder to see the difference than my Dirt texture.
Lastly here is my Dirt Material Function, it is pretty standard used the texture images as I got them.
Link to all images: Here