ultramarine
adj//ˌəltɹəməˈɹin//ultramarin
Of a brilliant dark blue or slightly purplish color like that of the pigment (noun sense 1).
In full ultramarine blue: a brilliant blue pigment traditionally made from ground-up lapis lazuli, and now usually either extracted from mineral deposits or made synthetically.
A brilliant dark blue or slightly purplish colour like that of the pigment.