Thanks so much for your thoughts..
glass tiles... while it would look so pretty, I am a little apprehensive about it because we aren't using glass tile anywhere else in the pool and I am worried it would look out of place? Stone would be too rough to sit on, would make picks on swimsuit bottoms, etc... hmm, I am at a loss. I wonder if just adding the shimmering or glass beads to the plaster that goes on top of them would add enough to make them stand out?
Also, looking at our waterline tile choice, what color grout would you go with? There is so much variation between the tiles, I am unsure. For inside the house, I love white/bone colored grout because I like light and bright but I am not sure about how much that would discolor in the water.