Chevreul
Chemist Michel-Eugene Chevreul (1786-1889) was the director of dyes at the national Gobelins textile factory in Paris. Chevreul identified a fundamental law of the simultaneous contrast of colors which detailed the effects that proximity between two colors has on what the eye sees.
Chevreul’s color model represented the complete range of shades, tones and tins of every hue, but his concept of tone confounded lightness (value) and saturation.