Abstract: The late Knut Nordby was a real-life counterpart of Mary: a color-blind expert in the science of color vision. This chapter describes the results of empirical research on color vision and other sense modalities. Based on these results and his own experience, he argues that Mary will be able to sense and discriminate color hues, but will not be able to name them on the basis of her knowledge. He does not take a definite stand on the epistemic and metaphysical gaps. But his reflections should help inform views on these matters.

Keywords: Knut Norby, color vision, senses, Mary,