In the past artists did not go to the shop buying colours. Was incredibly hard and sometimes very expensive.
Described as the “most perfect” of all colors, the ultramarine was originally made by grinding lapis lazuli into a powder. Whether it was for an Egyptian royal tomb of 5000 years ago or for nobless jewels, ultamarine pigments came all from Badakhshan, a region of modern Afghanistan.
Ultramarine was the finest and most expensive blue used by Renaissance painters, and the name itself (literally “beyond the sea”) is related to the fact that it came to Italy from that region.
Yves Klein in modern age became famous for his study about colours, especially a deep tone of blue now patented under the name International Klein Blue (IKB). The artist used the ultramarine as core of this new colour.