take care of the dyes of wools and silks used by the three manufactures, the most important being that of tapestries (Gobelins). The Director of the Department had indeed among other tasks that of looking after the quality of the wool (that had to be cleaned from grease and bleached) and the quality of the dyes according to their stability, their brilliance, and the kind of cloth to which they had to be applied (basically wool, silk, and cotton). Another important issue was that of color classification.

Before focusing this essay on the law of simultaneous contrast of color, it is worth noting the wide range of interests Chevreul had for colors. He himself suggested a classification of his work on color. The two main categories are (a) meansthe first being published in 1807, when he was 20 years old [11]. His interest for animal fat also helped him to work on the process of degreasing and of bleaching dyes, to which he devoted numerous papers.

Although Chevreul’s work on color covers many aspects, his most important contribution to color is his law of simultaneous contrast of colors, as expounded in his book translated into English under the title The Principles of Harmony and Contrast of Colours and their Application to the Arts (1st edition in French, 1839; 1st English translation, 1854). Its starting point was a complaint from the weavers of the Gobelins against the dyers of the Department of Dyeing that he directed. The complaint was in particular about the black samples of wool used