Testing shows that coloured pigments display the same optical behaviour in mixtures with achromatic pigments. This applies to white pigments as well as to aluminium and white interference pigments. However, the way that coloured pigments react in a mixing series differs for green and blue-coloured pigments compared with yellow and red-coloured pigments. The range of coloured pigments includes both inorganic and organic pigments. Both groups can be further divided based on their chemical structure. For these experiments into the optical properties of coloured pigments, we mixed tints in several mixing steps with a white tint as well as ...