even that's dubious.. sanji hasn't used CoA in Manga..
a fist fighter like Luffy constantly uses it..
how tf has this guy made it this far?
It may be just inconsistence, Oda used to draw haki for Zoro's hands and swords, but it is barely being shown anymore, only his swords are black most of the time, but for Luffy he draws it the whole the time.
Sanji kicked Queen and Queen used haki, but we can't see Sanji using it. As i said, its just something aesthetical for Sanji that Oda prefers to stick with, perhaps with the excuse that "it isn't shown cuz Sanji uses pants and shoes", even then you have moments where characters are using haki beneath their clothes and the clothes also get black, and at other times it simply doesn't, i remember this happened with Vergo and Smoker for example but im sure they aren't the only ones.