I’d call that an optical illusion caused by light reflecting off of black screws.
Now that we know the on-location screws were also black (and the “silver” look an optical illusion caused by snow), I think we can safely assume that the screws were consistently black during the entire production.
Think logically about it. The screws and notches were a production necessity, NOT a stylistic design choice. Therefore, they would have wanted to keep their solution for holding the grips on as discrete and unobtrusive as possible. Thus, black screws to blend in with the black grips. We weren’t supposed to ever see them onscreen.
Now that we know the on-location screws were also black (and the “silver” look an optical illusion caused by snow), I think we can safely assume that the screws were consistently black during the entire production.
Think logically about it. The screws and notches were a production necessity, NOT a stylistic design choice. Therefore, they would have wanted to keep their solution for holding the grips on as discrete and unobtrusive as possible. Thus, black screws to blend in with the black grips. We weren’t supposed to ever see them onscreen.