It was just a tool I used to create the some screenshots. I did not include the script in the package but I forgot to remove the object using it from the demo scene. I fixed this in the new version.
Surface projection is done on colliders. Does your terrain have a collider?
My terrain has the terrain collider attached to it. Does the system by any chance have frustum culling built-in for better performance, like the GrassViewdistance, if not I will just implement it myself 
EDIT: None of the grass seems to have color too. I have no idea if this is by accident or not, just mentioning it. You might be able to tell me.
I tested the system on some terrains and I had problems getting it to work. I have no idea why. I am sorry.
It seems like sometimes the terrain got a collider and sometimes it don’t.
No it does not have frustum culling.
I like to control the grass color from within the game. By making the texture gray-scale, I can tint it when I render.
Adjusting the material color for every cluster of grass is not very effective. Instead we can apply it to the vertex color. This require a custom shader. I included one in the package.