R. Luther, N. D. Nyberg
The sophisticated construction is a response to the question as to which solid would be revealed through accommodation of the tangible, real colour pigments. The answer requires complex colour measurements and corresponding stimulus formulae, and can be attained only by mathematical means. The figure shown arises in the vector-space of colours when the so-called “Luther units of measurement” are used. It is amusing to think that just when the two physicists were attempting to replace the subjective element in the construction of colour-solids with objective criteria, their colleagues were being compelled to make a radical change and view atoms in the opposite way: in the mid-twenties, it was becoming increasingly obvious that the influence of the observer, even in the exactness of physics, could no longer be ignored and that a subjective component was unavoidable. (Detailed text)
Date: The two physicists Luther and Nyberg evolved their colour-solids in 1927 and 1928 respectively, during the course of their work on the measurement of colour stimulus.
Basic colours: Yellow, green, blue and purple
Form: Colour-solid constructed around the vertical black-white axis.
Related systems: Ebbinghaus — Ostwald — Pope — CIE
Bibliography: R. Luther, «Aus dem Gebiet der Farbreizmetrik», Zeitschrift für technische Physik 8, pp. 540-558 (1927); N. D. Nyberg, «Zum Aufbau des Farbenkörpers im Raum aller Lichtempfindungen», Zeitschrift für Physik 52, pp. 406-410 (1928); M. Richter, «Einführung in die Farbmetrik», Berlin 1976.