I can recall tasting something and describing it as "purple". My friends were confused, because what I actually meant was that the flavor reminded me of artificial grape flavoring, and those things tend to be purple in color.
It's funny because my mind doesn't associate artificial grape flavoring with the flavor of a real grape or grape juice, since the flavor of real grape is so much more complex and different, so it associates that artificial flavor primarily with just the color purple.
Purple Kool-Aid, purple Flavor Ice, purple Gobstoppers, they all taste
like purple to me!
Everytime I drink Guinness, or any other strong stout, the sensation of "black" is appearing in my mind, probably because of the color that it is, and also associating it with other black things like black coffee, motor oil, or ash - essentially a very earthy flavor.