What color is the ocean?
The Real Answer
The ocean often looks blue because water absorbs longer wavelengths of visible light, especially reds, more strongly than shorter blue wavelengths, while scattering and particles help determine what light returns to your eyes. The exact color can shift with depth, algae, suspended sediment, weather, and viewing conditions. This is not simply the same Rayleigh-scattering mechanism that makes Earth's sky blue.
You stand at the beach, call the ocean 'blue,' and move on as though a body of water that shifts from turquoise to gray to almost black picked one paint color. Then you take a photo and blame the camera because the water chose a different blue than you remember.
The Dunce Dynamics Institute Examines Why People Ask This
The ocean looks so consistently blue in pictures that it feels like the water must simply be blue. The more interesting answer is that water selectively removes wavelengths and the scene keeps changing with depth, particles, and light.