The first known artificial blue pigment, Egyptian blue (calcium copper silicate) was in use in Egypt by ca. 3200 BCE. The pigment was produced by firing quartz sand, lime, copper and an alkali flux in a kiln. It was used widely as a colorant in the ancient Mediterranean world and Near East. Web resource here.
Cup containing Egyptian blue pigment from Pompeii. 1st c. CE. Soprintendenza Pompei, inv. 18106. Photo: Dan Diffendale.