When light shines on the water surface, the different colors are absorbed, transmitted, scattered, or reflected in differing intensities by water molecules and other so-called optically active constituents in suspension in the upper layer (called the epipelagic or photic zone) of the ocean. The reason that open-ocean waters appear blue under clear conditions midday is due to the absorption and scattering of light. The wavelengths of blue are scattered, similar to the scattering of blue light in the sky, but absorption is a much larger factor than scattering for the clear ocean water. In water, absorption is strong in the red and weak in the blue, and so red is absorbed quickly in the ocean, leaving blue. Almost all sunlight that enters the ocean is absorbed, except very near the coast. The wavelengths of red, yellow, and green are absorbed by water molecules in the ocean.