The first wavelength, 750 nanometers, induces the sensation we call “red.” The second, 500 nanometers, induces the sensation we call “green.” And 400 nanometers induces the sensation we call “violet.” The language in the preceding sentences has been carefully chosen in order to make it clear that the “color” is not in the stimulus itself (i.e., a light wave), but is produced by the firing of a certain kind of photoreceptor.According to the passage, we can see the color violet at a wavelength of