Great story from Fast Company:
What vaulted FiftyThree over a hot pile of math was a major insight gleaned from two dead German scientists named Paul Kubelka and Franz Munk. In 1931, they published a paper called Ein Beitrag zur Optik der Farbanstriche, or “a contribution to the optics of paints,” which showed that this color-space question predated computing by several decades. The paper laid out a “theory of reflectance” with an equation which could model color blending on the physical experience you have with the naked eye. That is, how light is reflected or absorbed by various colors.
Today, computers store color as three values: one for red, green and blue, also known as RGB channels. But the Kubelka-Munk model had at least six values for each color, including reflection and absorption values for each of the RGB colors. “While the appearance of a color on a screen can be described in three dimensions, the blending of color actually is happening in a six dimensional space,” explains Georg Petschnigg, FiftyThree’s cofounder and CEO. The Kubelka-Munk paper had allowed the team to translate an aesthetic problem into a mathematical framework.