Περὶ χρωμάτων (Peri chrōmatōn): Colour formation and investigation method

In this essay, the attention is focused on the method used to investigate colours, as produced in nature. This method was proposed by the author of the treatise Peri chrōmatōn, which has become part of the Corpus Aristotelicum. The colours are first divided into two large categories, simple and mixed, in accordance with other scientific and philosophical approaches. Simple (primary) colours are considered to be white and yellow, and are associated with the elements (air, water, earth, and fire/sun); black is also associated with the elements as they transform into one another. This division is new in comparison with previous theories based on two or four fundamental colours. The endless range of colours seen in objects, plants and animals, is connected to the mechanisms of mixing different qualities and quantities, inherent in what it comes into contact with, and in the consequent changes, in conditions and states of matter, in the incidence of light, qualitatively and quantitatively different. The heuristic reference scheme and the analogical model are represented by the dyeing process. The essentially phenomenological treatise contains historically significant insights: no colour can be seen in its purity; the reciprocal interaction of colours; the variability of conditions that determine the chromatic impression; light as a component of mixtures, and its diversity depending on the source; and the chromatic value of shade. In it, we can also see the formation of a classification of colours and a nomenclature, founded on the relationship of distinct chromatic notations with light and darkness