The most direct way to make such a change is through a map's load.ini file, where the water color is set via the R, G and B color channels. Note that the texture itself is typically some shade of blue, but by altering the 3 color values one has pretty wise scope for setting a desired color.
A more global change can be effected by use of an after effects application, such as Reshade. There are a variety of preset video colorizing enhancements which might get you nearer to your desired color palette. Of course, this impacts the entire gamut to at least some extent, and so a more limited alteration of water hue is possible without ending up with a rather radical change to the whole scene.