Uncertain how accurate this is.
Keith.
"Titanic" had been granted an Admiralty warrant to fly the Blue Ensign from her stern flagpole. It indicated that
she was British (although she in fact was owned by IMM, a US based trust),
Captain Edward J. Smith was a Royal Navy Reserve officer and
a specified number of crew members were RNR, too.
The Blue Ensign made "Titanic" something special among other British merchant vessels, which normally were required to fly the Red Ensign, also nicknamed the "Red Duster".
All Things TITANIC - Blue Ensign
May also be worth a read:
The Titanic Photos of Fr Browne | A Unique Glimpse Onboard
Keith.