In an SBS, Eiichiro Oda, the creator of One Piece, was requested concerning the Haki users within the Strawhat Pirates, and at that moment, there were just three.
D: This might be out of nowhere, but who in the Straw Hat Pirates can use Haki? It’s bothering me and I can’t activate my “Love Hurricane”.
Oda: It’s these three. Their specialty haki color is in the parentheses.
Of course this doesn’t mean that they will not power up on the other types of Haki (e.g. Luffy is trying to see a bit of the future like Katakuri can see a few seconds, or more, into the future).
Simply, they’ll be Masters of each different Haki.
Zoro – Master of Busoshoku Haki
Sanji – Master of Kenbunshoku Haki
Luffy – Master of Haoshoku Haki
