On Colors or On Colours (Greek Περὶ χρωμάτων, Latin De Coloribus) is a treatise traditionally attributed to Aristotle, but now sometimes thought to be by Theophrastus or Strato, who succeeded him in turn as heads of his philosophical school, the Lyceum. The book's argument, that all colors are derived from the mixture of black and white, was an important influence on subsequent color theories until the time of Newton.
Free online and downloadable texts
Wikisource: Περί χρωμάτων - Greek text. HTML format.
New Republic: Does Color Even Exist? by Malcolm Harris 22 May 2015.
Open Book - Rare Books Department of Special Collections at the J. Willard Marriott Library, The University of Utah -Book of the Week — De coloribus libellus, 5 December 2016.
Princeton University Press: Why the Sky is Blue: Discovering the Color of Life, by Götz Hoeppe. Chapter Two - Of Philosophers and the Color Blue.
Stanford Encyclopedia of Philosophy: Controversies Surrounding Aristotle's Theory of Perception, by Christopher Shields.
Wikipedia: On Colors
University of Massachussets - Amherst: Greek Color Theory and the Four Elements (2000). Chapter Two - Greek Color Theory by J.L. Benson.
Youtube: On Colours, by Aristotle. audiobook read by Geoffrey Edwards
The Great Conversation: Further reading at Tom's Learning Notes
Ancient Greek resources: Learn to read Greek classics in the original.