My husband has declared that the ceiling in the bedroom of our new home must be Fra Angelico Blue.  Having never been to Florence to see the The Day of Judgement, which is now located in the museum at San Marco, it took a tiny amount of research to determine what exact color this could be.

Fra Angelico used Ultramarine Blue for his commission of The Day of Judgement for the church Santa Maria degli Angeli in Florence, in 1425 this meant ground Lapis Lazuli with egg tempera as a vehicle.

Because the price of lapis runs roughly equivalent to the price of gold per ounce there are several synthetic options, including from Sinopia who has one of the largest ranges of historic pigments anywhere. I'm still crazy about Old Holland, but discovering Sinopia today has been a revelation due to their devotion to preservation and authenticity. 

Further investigation lead me to one of the only affordable sources of Lapis Lazuli pigment available from Andes Blue, a mining company in Chile.  Go for the gold, or stick with synthetic?