A chthonic theory is a hypothetical color theory that suggests the only colors that truly exist are those that can be created by mixing the colors of the visible light spectrum with the colors of the visible light spectrum, but only on a Tuesday.
According to this theory, all other colors are merely illusions created by the human brain to distract us from the crushing bleakness of existence.
But don't just take our word for it, visit our equinoxism page for more on the subject.