We are having a pool built in our backyard. They are doing the stone work around the pool and are putting in a tiered waterfall made out of flagstone. The waterfall is 12' wide, 3' deep, and 2' high. I originally only wanted to use brown flagstone, but since there are drystack flagstone walls and columns around the pool with some charcoal in them, I agreed that a small amount of charcoal flagstone could be put in the waterfall. The waterfall is about half done and I don't really love it-to me some of the charcoal pieces stick out like a sore thumb. However, the piece that sticks out the most is on the bottom of the waterfall (there are 10 2.5" layers of stone).

My questions:

1. If I ask them to replace a stone, can they just pull this piece out, or will they have to disassemble all of the pieces on top of it also? I'm guessing they will have to disassemble since they will need to make sure the stone is waterproof.

2. Can I paint the stones that I think are too charcoal? Will paint stay on flagstone that is part of a waterfall?

The waterfall is the focal point of the pool and I really want to love it. I can post pictures if it would be helpful. I guess it is possible that once the entire waterfall is built, the pieces won't seem to stick out as much as they do now.