Problem: Selecting Large Regions in Terrain Paint Mode

This somewhat works. However, the material of my landscape is a blend between grass, rock and gravel. I have to opt to repaint the entire landscape with a single layer (grass, gravel or rock) before painting with either of these on specific regions will work properly. The issue with this is that if I opt to repaint the entire landscape with “Grass”, it doesn’t look the same as the rock/grass/gravel blend as shown in the picture.

Am I doing something wrong or misunderstanding the suggestion?

Edit: I attempted to paint the entire landscape with rock, ground and then grass. It seemed like it was going to work and then the software crashed (report submitted with this URL in the description). It worked previously, I think I was trying to paint too fast.

Edit2: Restarting UE4 seemed to correct the difference in the color, I can’t explain why.