Trimesh and Terrainblocks

I'm trying to make a territory control game and I'm currently using a TerrainBlock for the ground.  I wanted some way to show what areas of the world you controlled by changing the color  of the ground once it was capture.  It looks like trimesh would be the best choice because it can blend the different colors together.  Is there a way to use the terrainblock and change the colors like with the trimesh?

TerrainBlock is a subtype of Trimesh…