The Color Top and the Distinction Between Additive and Subtractive Color Mixing

The article provides a brief overview of the history of the color top as a research instrument. Specific focus is given to James Clerk Maxwell’s experiments, which allowed him to obtain the first colorimetric equations using this simple device, and to Hermann von Helmholtz’s use of the top to exhibit, in a very simple and clear manner, the difference between additive and subtractive color mixture. As a matter of fact, among Maxwell’s and Helmholtz’s key contributions to the theory of color, it is worth mentioning that they clarified, for the first time and independently from one another, the distinction between additive and subtractive color mixing, eliminating definitively Newton’s confusion between the optical and pigment mixture of colors.