plural of ultramarine

(archaic) Beyond the sea. / Of a brilliant dark blue or slightly purplish colour like that of the pigment (noun sense 1).

In full ultramarine blue: a brilliant blue pigment that was traditionally made from ground-up lapis lazuli, and now usually either extracted from mineral deposits or made synthetically.

A pigment which is the residuum of lapis lazuli after the ultramarine has been extracted, and which was formerly used as a middle or neutral tint for flesh, skies, and draperies.

A green pigment obtained as a first product in the manufacture of ultramarine, into which it is changed by subsequent treatment.

plural of ultramarine ash