Alright; here's my idea:
You know how the Fill Can works? Well, I think this should work the same way; Equip the tool, spray a certain-colored brick, and all the bricks touching that one that is the same color loses ray-casting. Why do we need this? It may be helpful when making top-down Deathmatches, but you can't really edit anything without totally screwing it up.
I would do this myself, but I can't program worth crap.
Thanks in advance!