ultramarine

Short definition from Wiktionary

Adjective

1. 1
   Beyond the sea.
2. 2
   Of a brilliant dark blue or slightly purplish color like that of the pigment (noun sense 1).

Noun

1. 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.
2. 2
   A brilliant dark blue or slightly purplish colour like that of the pigment.