This is doable, the effect that you want to achieve could mostly be made by adjusting the ocean settings themselves. Some devs use a tinted terrain texture underneath the water also to help with the color if they can't get it just the way they like it, to great effect I might add.
Ocean color and fog is under Environment Editor->Advanced. The brighter the color generally the more fog, so choose a darker shade of the color you want and increase the multipliers instead.
Most of the other settings will be in the shader parameters for the ocean.
For water volumes, these settings will be the same (ish) for the shader parameters of the material, and the fog color etc settings will be in the actual properties of the water volume itself.