It is hard to see in the images above but the shadows are all different color.
That was deliberate too actually for an obvious different reference.
In some of my tests they looked quite distinct.
I was a little surprised that Terragen mimics the real nature in this way too as i expected the shadows as black actually.
Given the nature of Terragen and Matt's approach i should have expected (maybe i have forgotten that this was already so since many years?)
this maybe but still nice to see.
Maybe interesting for some of you:
https://www.youtube.com/watch?v=sBUdhgcIjXo