I'm amused that the author chose a centuries old color name that's been in relatively frequent written use all that time for the title. The article centers on

I'm amused that the author chose a centuries old color name that's been in relatively frequent written use all that time for the title. The article centers on the history behind huge catalogs number of obscure color names, but he chose one that's not at all obscure. OTOH it's kind of a win because cerulean isn't the generic "blue" most people would think of, so it nicely illustrates the use of distinguishing color names.