Rivers, and water in general usually reflects the ambient light/sky conditions which makes water appear in all different clarities and colours. But that is only one of the factors.
Color changes together with how much soil/sand is being stirred up, what kind of algae lives in the water, what kind of bed the river/ocean is flowing over, how deep it is etc etc et, the list goes on...
Feel free to take the time to change the colour of every single river and how it acts during very many different conditions to suit your liking.
May I point out, so you don't misunderstand me, that I do not think the river and ocean looks realistic in the colour aspect as it doesn't represent the ambient conditions. But even though there are SO many other things to fix that are actually important or dare I say urgent that this is the wrong time to complain about it.
Wait until other stuff is fixed and the devs are actually trying to create new stuff and content, rather than mending and patching up old content, before you bring up negligible stuff like this. Just my two cents
I just seriously don't need another thread full of pics and screenshots of real rivers and game rivers arguing over the colours.
It's also perfect timing since they already fixed/upgraded the colours in the latest patch