Is the colour of the sea the same everywhere?

Is the colour of the sea the same everywhere?

Though we always think of the sea as being blue in colour, the water of the Red Sea has a slight reddish tinge to it, because of the algae that lives in this sea. This algae clouds and muddies the blue water.

The Black Sea contains a lot of hydrogen sulphide, which gives the water a blackish tinge. Being further north than the Mediterranean Sea and much less salty, it also contains more micro algae, which makes its deep waters very dark.