NOAA Greenish-blue light transmits through the water behind the exploring NOAA robot. I know it has something to do with wavelengths, but I don't really understand it. Water transmits light of every color and, therefore, looks clear. The clearness enables you to see colors of an underwater object near to the surface.
Water is clearest for colors of shortest wavelengths-the blues and greens.
This effect is most noticeable in the water looking up. Looking down at the water surface can change the apparent color of the water body due to light reflections and refractions. Water isn't perfectly clear, though, especially for colors with longer wavelengths. White light consists of red plus its complement, greenish-blue light. So absorbing orange and red leaves greenish-blue, the intrinsic color of water.