Yes it is. There is one on the water next to the ship also, but i removed it from the photo. I have another foto from a different angle that shows the towers better, but they are in the way of the ship so i didn't develop them.
EDIT: Looks like it is not painted (not by humans at least). I thought that the 'crate' on the left side was a part of the same "paint" as the blue parts but it looks like i was wrong. The nice colors appear to be sediments "painted" on the ship by the tides. It was low water, lucky me