Here is an interesting article on converting between color and sound:
a color blind artist uses a machine that identifies the color spectrum by associating the color's light wavelength with an equivalent sound wavelength; the artist hears the sound and identifies it with a color.
One wonders what shifts in perception a non-color blind artist would experience with such a machine that was out of sync ... hear blue and see green ... a headache?(probably). Would the visual input override the aural input? or would the aural and visual color input blend in the brain to a combined output color? I don't know enough about how color is processed in the brain, but it does remind me of the a small group of people who can see colors when they hear sounds -- synesthetic perceptions.