I joined a French & Indian/Revolutionary War re-enactment unit last year. We re-enact the 77th (F&I) and 42nd. We have diced hose and red trim on our Balmorals. Interestingly enough, a miltary artist, Don Troiani, has a painting out, "Sword of the Blackwatch", that shows the 42nd in black hose.

As I said originally, "...as I understand it..." My guess is nobody knows anything for sure.