Introduction_to_oceanography when asked to color the ocean, most of us would choose blue for the ocean. is it true that the ocean is blue? what makes the color of the ocean?

Water absorbs all the longer wavelengths and reflects the shorter blue wavelength.

Explanation:

First let us examine how the human eye perceives color. When we see a red object the object is not inherently red, rather the surface of the object reflects wavelength corresponding to the red color and absorbs the rest of the spectrum.

The ocean consists mainly water. Water has a slight blue tint and not completely colorless. When we see water it is of considerably less volume compared to the ocean. So, when we see water of such a large volume in the ocean the blue tint becomes more apparent. This means that water absorbs all the longer wavelengths and reflects the shorter blue wavelength.