Well, the most easy thing will be to play a little with the colouring of "Ocean".Got everything but muddy waters so far, but some colors looked more riverish.
I can do so much 2D graphical work myself - although I am not an expert.
But you can send what you have so we can look at it.
Might save us some time and effort.
Thanks for the offer, we might get back to it.I could give it a shot at making a lake button as well.
But let me ask @Zeta Nexus maybe first, because I love his Terrain buttons.