I know the 10th regiment of Foot up in MA area, and the Royal Welsh still follow this rule... but Delancy's were the only troops I ever saw actually wearing a muted brick red colour... I don't even know if any of them are still about... I know that the 10th has what they believe to be crimson from the time frame that is very orange in colour...for their officers.
But with age I wonder, and maybe Kass can elaborate on this a bit more, how many "True" colours we are actually seeing on display in museums, or if the colours have faded too much over the years...perhaps if one was to rip open a lining that would help to judge better...
We followed the rule of better fabrics for officers but unfortunately the current 17th/21st Lancers were actually looking to us for information as no one in their ranks was ever interested in following the history of their regiment... When I went to Beaver castle to meet with the Lt. Colonel and discuss matters, the first thing he asked was that we donate some of our kit to the museum... what they had for Rev. War period was actually one of their Napoleonic period coats... The only helmet that still exists is in France... George Neuman went and took detailed pictures of it for us.