In 1975, the Dutchman J. Frans Gerritsen made a fresh attempt at arranging colours according to the laws of colour perception. He arranges them in such a way that complementary pairs lie diametrically opposite each other, with three brighter colours alternating with three darker colours. All conceivable primary and secondary colours can therefore be placed both on the cylinder wall and on the wave line. Gerritsen identifies the achromatic colours running from white via all the grey tones to black as tertiary colours. The two illustrations show vertical and horizontal sections through the perceptual colour-space as shown to the left.
Horizontal sections exhibit colours of the same brightness.
Gerritsen wished to use his model to rediscover some of the old laws. Red as a 'mixed colour', once believed to occur between black and white, is found on the outer circumference between black and white. Newton's colours of the daylight spectrum are given their rightful place. Three different genes have been located, which are responsible for three pigments of blue, green and red. For simplicity's sake, we shall here talk of blue, red and green genes.