How did Wilhelm Ostwald contribute to colour theory later in life?

After retiring in 1906, Wilhelm Ostwald embarked on a second scientific career focused on colour theory, driven by his lifelong passion for painting. Applying the same rigorous, multilevel approach he used in his earlier chemical research, he made several significant contributions:1

• Measurement and Classification: He developed instruments to measure colours and created a sophisticated classification system to derive mathematical laws of harmony. This system is based on specific mixtures of white, black, and a high-chroma colour.12
• Production and Education: He produced physical colour specimens in his laboratory, founded a factory to manufacture paint boxes, and actively advocated for reforms in artistic education.1
• Literature: He authored numerous textbooks detailing his theories and the history of colour.1

Through these efforts, Ostwald sought to bring scientific precision to the study of colour, influencing both the artistic and scientific communities of his time.1