Depends on the character of black used. If the black is mixed with bluish ingredients or neutral ingredients which are brownish. The former will have a slight bluish cast, the later none. As I understand it, RN captains paid out of their pockets for ship paint in the high Victorian period (no captains from poor families) so, it is possible either black was used. This is a question for the owner of Sovereign Hobbies who is the best RN paint authority.