Once long ago, blue was the most expensive pigment used in painting. Now with modern production methods an affordable palette of rich and vibrant blues is available to all types of artists. When man-made blue became readily available so did an endless variety of violets. Cobalt Blue, Prussian Blue, Cobalt Violet, and Phathlo Blue are very common colors to artists today. Sinopia sells completely lightfast blue and violet pigments that are compatible in any medium and with each other.