This armor has some kind of weird and unnecessary layer that makes it have a purple tint when dyed black in game. This tint is completely absent in all cut scenes, regardless of the lighting in the scene. It also is not present in the character loading screen or the character dummy. This seems buggy in nature. The other reason it seems like a bug is because there are two parts of the shoulder which have the exact same texture and one part has the issue and the other doesn't. I've attached a link to screenshot.
This shows the purple tint that's seen in the game world.
https://media.giphy.com/media/E9i67x016VH83RZnNe/giphy.gif
This shows how it should be and how its shown in cut scenes and character dummy.
https://media.giphy.com/media/r82REJy7zxxpd7GZeF/giphy.gif