There's that, and then there's coloring the water.....
when water is blue or green or whatever, where does the color come from?
I swim in a pool in the summer that is painted white every spring. It has green water.
But why worry about the quality when the rest of the rendering is so murky.
[I am just teasing.]
The best result will be to map the inside of the pool with a photo of light diffractions in a pool.
Dwight Atkinson