Yves Saint Laurent’s fall 1965 collection was inspired by the paintings of Piet Mondrian. While it became one of Saint Laurent’s most famous collections, other designers had introduced similar designs before him. The Montreal Gazette claimed that color-blocked dresses by Michele Roiser had inspired Saint Laurent to “add a few black lines” to his own creations. View some of the collections here: https://teranicouture.com/collection/evening-dresses-2016-and-2017
YSL dress seen here with a color block design by Lousi Feraud (circa 1967) on the left.