Nico Robin haki kick color by xMrNothingx on DeviantArt

While Sanji was in Nami's body he used sky walk, does that mean

One Piece Gold - Rob Lucci's vivre card said that: The training required for the acquisition of rokushiki is akin to that used for acquiring haki. Akin = in the family Rokushiki

Rokushiki, Wiki

Rokuogan, One Piece Wiki

Tekkai, One Piece Wiki

Shigan, One Piece Wiki

Which do you prefer in One Piece, Devil Fruit, Haki or Rokushiki? - Quora

Konoha: Deduce Rokushiki and Armament Haki at the Start! Latest Chapter - MTLNATION

Rokushiki - Desciclopédia

Rokushiki Robin 34 by Shinjojin on DeviantArt