Researching colour

Sir Isaac Newton was the first person to shine sunlight through a prism and break it down into its various colour components. The spectrum begins with red and ends with violet. He drew a circle, put the spectral colours in order, and closed the gap between red and violet with magenta (purple). Starting with Leonardo da Vinci, Isaac Newton and Johann Wolfgang von Goethe, and continuing to Philipp Otto Runge and Johannes Itten, history is full of individuals who have attempted to create a scientific order system for colour that can be explained objectively.

CIE-XYZ chromaticity diagram
The cone-shaped chromaticity diagram
developed by the Commission Internationale
de l'Eclairage (International Commission for
Illumination) shows the spectral colours as
a curve, closing it with the colour purple.
Because of its shape it is known in the
jargon as the "horseshoe". The so-called
white point is approximately at the middle
of the chart. Viewed three-dimensionally,
this is where all the white, grey and black
colours are. If one were to draw a straight
line from the white point in the direction
of the spectral colour (= edge of the chart),
then every colour in the same shade would
be on it, but with a different saturation. The further a colour is from the white point, the more saturated (brilliant) it is. The spectral colours are the most saturated colours there are.

Philipp Otto Runge (1777-1810)
The twelve colours of the colour spectrum are on the equatorial axis. The north pole is white, the south pole black. Moving upwards, the colours gradually become lighter in line with white, and they get darker towards the bottom with black. At the heart of the colour spectrum is a grey scale. Towards the centre of the spectrum the intensity of the surface colours weakens, so they gradually approach grey. The complementary colours are achieved by reflection at the centre point.

Johannes Itten
The colour spectrum designed by the Swiss painter and Bauhaus pedagogue Johannes Itten (1888-1967) uses the three primary colours red, yellow and blue, and mixes from them the three secondary colours orange, green and violet, and obtains six further tertiary colours from these. The colours of the ring roughly follow the course of the spectral colour band. Two complementary colours such as red and green are opposite each other on the spectrum. There are, however, certain limitations to colour combinations. This is where the colour spectrum of the artist Philipp Otto Runge opens up a deeper dimension of mixing.

Goethe's colour spectrum
If a ray of light breaks up on an object – as in a rainbow – and is thrown back by it (refraction), the colours of the spectrum become visible. Johann Wolfgang von Goethe (1749-1832) studied this phenomenon and defined it in a colour spectrum. The spectrum consists of a basic triangle with the colours yellow, blue and red at its tips.