It is interesting that the sword Zack has does not have the gold plating on it especially when other material has differentiated between Cloud's Buster Sword and Zack's Buster Sword.
FFRK Buster Sword (FFVII)
FFRK Buster Sword (FFVII-CC)
FFRK Hewley Buster (FFVII-CC)
World of Final Fantasy: Meli-Melo
World of Final Fantasy
World of Final Fantasy
Pictlogica Final Fantasy
Pictlogica Final Fantasy
Opera Omnia
Opera Omnia
Final Fantasy Airborne Brigade
Final Fantasy Airborne Brigade
Theatrythm Final Fantasy All-Star Carnival
Theatrythm Final Fantasy All-Star Carnival
The only exception that I can find is FFBE. Both Cloud and Zack do not, from what I can see, have gold on their swords.
For funsies, here is a photo that the Final Fantasy wiki stated this is an in-game render from the old engine of Dissidia NT Arcade:
Then, here is a different photo from Dissidia NT (updated) without the gold plating.
I understand that this is a Remake and it doesn't have to follow previously set expectations, but I was always used to gold plating = Zack. So, it throws me off that Zack's Buster Sword doesn't have it.