This author is confusing light frequency with color. Color is a physiological and psychological influenced mental perception. What color we see varies from sit

This author is confusing light frequency with color. Color is a physiological and psychological influenced mental perception. What color we see varies from situation to situation and person to person. While we are often unaware of how subjective our perception in response to light is, it is quite subjective. In this context, the only way that I think matters, both black and white are colors. They are perceived and understood in exactly the same way that the frequency of light is perceived.