Real stone is not recommended for submerged use like pool waterline tile and steps because the chlorine and other chemicals can fade the stones color quickly. Although, if you have a rugged stone such as these flagstones and don't mind a little color fading, stone steps in the pool can be a very handsome look.
This antique limestone paving without filling in the interior of Hearst Castle looks a lot like travertine. It has a nice patina to it that only comes with age. You can darken stone with tinted sealers and stains, but the color will be much more uniform than this.
