Edit: For some reason I had a black border around my decoration file, I have no idea how I didn't notice it before. Sorry. 😄

When I add a custom decoration to the new stingray part (67337), the part colour of all of the areas of the part which are not UV unwrapped becomes black.


The only instance of this colour in my decoration is the eye section. While this is slightly bigger than on the official part, it's still well within the UV boundaries, and it's on the opposite end of the UV map to the all of the sections of the mesh which haven't been unwrapped.