Deep sea has an intense blue color. The light that penetrates the water changes its light intensity and its spectral composition by effect of  selective absorption by water of the different wavelengths that make up the visible spectrum. The ultraviolet and infrared stop the first few centimeters of depth, then extinguished the red, orange, yellow, green and purple and blue that reaches greater depths. ...

The Emperor Angelfish (Pomacanthus imperator) is a species of marine angelfish. It is a reef-associated fish, native to the Indian and Pacific Oceans, from Red Sea to Hawai and the Austral Islands. This species is generally associated with stable populations and faces no major threats of extinction. It is a favorite of photographers, artists, and aquarists because of its unique, brilliant pattern of coloration.