Water Colors

Water will prevalently reflex the colors of the surrounding (including skies), but sometimes it will seem to have color of its own. Coloring can be caused by some biochemically natural or from some human-induced content... What color of water impressed you the most, regardless of the color source? It can be just water in the glass reflecting the sunset, or it can be the ocean surface under heavy clouds, the blooming of algae, some kind of pollution... or anything inbetween. Let's see the water colors as you have seen them. And if you know where that color came from, include that information in your description.