Jacob Christoph Le Blon, or Jakob Christoffel Le Blon, was a painter and engraver from Frankfurt who invented the system of three- and four-colour printing, using an RYBK color model similar to the modern CMYK system.[2] He used the mezzotint method to engrave three or four metal plates to make prints with a wide range of colours. His methods helped form the foundation for modern colour printing.

https://en.wikipedia.org/wiki/Jacob_Christoph_Le_Blon