from my notes: red light has a wavelength of ~660 nm I just did a question where I was asked to find the wavelength in water.. I got an answer of 470 nm. Just curious why the color doesnt change. (a red bathing suit is still red under water) I'm thinking the "red = wavelength of 660 nm" only applies to air, and that figure varies with different mediums. Is this the explaination?