So I’m wondering if there is a way to have grass placed on a terrain inherit the color of the terrain under it. So if I have a terrain that should have grass on it and the terrain is several different shades of green - I want the grass I place on it to take on whatever shade of green is below it. I only ask if this is possible because I remember a similar feature in the Cryengine and it was rather nifty.
Take a look at this thread: https://forums.unrealengine/showthread.php?22512-Getting-ground-color-for-grass 
I am interested in this as well. The thread you posted isn’t an ideal solution though, since if I understood correctly, the solution posted there requires a top down picture of the landscape. Is there any dynamic way of doing this?
you could set up a rendertarget that takes pictures of your landscape in the editor