I have just had the same dilemma re waterline tiles and I realised two things (if it helps)... Firstly it's the colour of the coping that I needed to match to, or compliment, the tile. And secondly, the colour of the tile matters if your pool is fully tiled, but if you are going with pebblecrete, then it's the colour of the pebblecrete that affects the colour of the pool and not the tile! First time pool builder, so who knew?! My fingers did do a lot of googling to decide on pebblecrete colours though. Good luck!

Barnes.... I actually know of a product that cleans that off with ease!!! It's new has had testing and has been through the process of intellectual property and is now currently under production. If you are interested I can try source you some.

Charcoal will give you more scope to mix in other items around the pool and is much more modern.

That's a beautiful finish and blends so well with the surrounding tiles. I'm curious what the coping tiles looked like before...are they the yellowish ones that are being painted in the 1st photo, or is that prep work being done? May I ask what was used to prepare the surface so paint would adhere? Great job!