text: what color is water really? obviously, it would seem as if pure water is transparent, but i read somewhere that water actually has a very slight blueish tint.  i think this may have something to do with the light being bent as it passes through or something.  sometimes you can even see a blueish color.  for example, when you fill up your bathtub several inches, you can see a slight blueish color.  also, lakes and the ocean can appear blueish, even when the sky is not a blue color to reflect. the absorption minimum for water is at 420 nm, well within the blue range of the visual spectrum. this means that that is the wavelength of light that it reflects the most. it does not reflect it very much, so small amounts appear transparent.