My partner was insistent on turquoise, a light blue, the pools at her developments are this colour, very nice I think, turns out to get this colour you use concrete coloured tiles, we bought a stone tile there a bit on the expensive side, while the tiler who is laying as I type I noticed you could hardly tell the difference between the tiles he's laying and the pre rendered concrete walls, to get an idea of colour im sure your pool has got water in it like mine, thats the colour, a light blue, looks awesome ....