ul ‧ tra ‧ ma ‧ rine /ˌʌltrəməˈriːn◂/ BrE AmE noun [uncountable]
[ Date: 1500-1600 ; Language: Medieval Latin ; Origin: ultramarinus 'coming from beyond the sea' ; because the substance it was made from was originally brought from Asia ]
a very bright blue colour
—ultramarine adjective