That is a good question! We know that Sir Isaac Newton, circa 1660, observed the rainbow when light based through a prism. The color waves, slightly bent at different angles revealed the full colors (seven) of the spectrum.

200 years later, Albert H. Munsell took Newton’s color theory to a whole new level. Munsell was an artist, & won some awards for his work in anatomy, perspective, and composition.

He developed the Munsell Color System which combined the art and science of color into a single-color theory, establishing an orderly system for accurately identifying every color that exists.   

Munsell defined that each color has three qualities:

1. Hue – color such as red, orange, yellow, etc.
2. Value – the lightness or darkness of a color
3. Chroma – the saturation or brilliance of a color

In 1909 Friedrich Wilhelm Ostwald (1853-1932), published “The Color Primer” and also “The Color Atlas” during 1916-1918. These publications established the relationships between the various visual colors. He also noticed that certain color combinations looked unpleasant, while others worked well together and concluded that color harmony was all about color order.

Bernice Kentner observes in her writings that the first discoverer of the "pot of rainbow color" was, the “unsung hero of color analysis,” Robert Dorr, circa 1928. An artist born in New York, he looked at people with a new eye and discovered the beautiful difference of skin tone. His trained eye for color saw blue and gold undertones in the complexions of people.
 
Ms. Kentner felt that this was the beginning of what we now call Color Analysis. In its first conception, people were placed in two categories with some basic similarities for their Color Key area. Mr. Dorr named his system "Color Key". He placed people in Key 1 or Key II colors. He recognized that all of us can wear any color of the rainbow if it has enough of the blue or gold pigment added to it to harmonize with the wearer’s personal skin tone.

The other person Ms. Kentner tells us about is Suzanne Cagill (1911-1994), a gifted color analyst from San Francisco, who helped people find their best colors for thirty years. Suzanne wrote her own book on color analysis entitled “Color the Essence of You.” Her book is a treasure of beautiful pictures and terms about the seasons of color. Her name will surely go down in history as one of the pioneers of the profession.

I am a graduate of Bernice Kentner’s Color Me A Season accredited course, which was officially recognized by the U.S. government. As a consultant with her company, Ms. Kentner personally reviewed our work each year, ensuring the highest standards of expertise.  CMAS is now overseen by her granddaughter. What an incredible gift Ms. Bernice Kentner has given me—the ability to help others discover their best style, colors, makeup, and skincare. Seeing their delight as they find personalized answers is truly rewarding.

Some information taken from: Sophia Knapp Jul 28, 2020

Rober Dorr (1905-1980) by Bernice Kentner (Color Me A Season)