Using smaller clouds and with a narrower contrast between the extreme (lightest and darkest) shades to them might help somewhat. You could also add a wide band of shallow water around the coasts that gradually fades off, so that you won't have deep water areas touching the coastline at any point. Applying some texture to the water might also do wonders, but that really depends on if you can find a good texture to use.

Personally I'd be tempted to experiment with a nearly 'flat', very dark-colored ocean. I think something like that could work quite well with this coloring and those landmasses.