The next major change in our vision when we are diving is that the colors often seem drab. This is because water absorbs light. Colors are simply light of different wavelengths and water absorbs them at different rates so that after light has passed through about 5 meters (16 feet) of water, most of the reds are absorbed. After 10 msw (33 fsw), the oranges are also absorbed.

The yellows disappear next followed by the greens and blues so that by the time we are deeper than about 20 MSW (66 fsw), everything appears bloc / grey. Using artificial lights restores the colors but the light from an underwater light is not exactly the same as the light from the sun and the colors will not be quite the same as if the object was out of the water.