The creation of three shades of blue hues — Prussian, cobalt and ultramarine — in 18th and 19th century European art, spanning from the Rococo period to Impressionism, is the subject of a colorful exhibition at the Norton Simon Museum, "A Revolution of the Palette: The First Synthetic Blues and Their Impact on French Artists."

"Previously, there were a limited number of options for oil painting," noted conservator and curator John Griswold. "Common indigo blue pigment did not stand up in oil, often turning to mushy gray."