Protan and deutan chromaticity coordinates from Wyszecki & Stiles

Data key


  1. Wavelength (nm)
  2. Protanopic b(λ) coordinate
  3. Protanopic r(λ) coordinate
  4. Deuteranopic b(λ) coordinate
  5. Deuteranopic r(λ) coordinate


Calculated from the CMFs of Table 3(5.14.2) of Wyszecki & Stiles (1982):














    These are theoretical functions derived from the positions of dichromatic confusion points in the CIE 1931 color space. Their validity depends on the validity of the CIE space, on the appropriate choice of confusion points, and on the assumption that dichromacy is a reduced form of the normal trichromacy.

Primaries 460 and 650 nm.

    Directly measured protanopic and deuteranopic chromaticity coordinates can be seen in Figs 2, 3 and 4 of Pitt (1935)--the same functions can also be seen in Figs 199, 206 and 207 of Wright (1946). We have not seen these functions in tabular form. Does anyone have them?


Pitt, F. H. G. (1935). Characteristics of dichromatic vision. Medical Research Council Special Report Series, No. 200. London: His Majesty's Stationery Office.

Wright, W. D. (1946) Researches on defective and normal colour vision. Henry Kimptom: London

Wyszecki, G. & Stiles, W. S. (1982). Color Science (2nd ed.). New York: Wiley.