Color and brightness fade-out in the Ganzfeld is wavelength dependent.

When watching a monochromatic Ganzfeld, three wavelength-related phenomena are perceived: (1) the field turns achromatic; (2) the initially bright field fades into a dark or a foggy, gray field; and (3) a sensation of an additional darkness is experienced upon light turn off. When a short wavelength is viewed, fading times are long and the sensation of additional darkness is strong while the inverse is true for long wavelengths viewing. At each wavelength, the magnitudes of all three phenomena are linearly related to the logarithm of the stimulus intensity. Possible physiological mechanisms underlying these phenomena are discussed.