Merde! Sometimes it is rather annoying to learn something new. My French being rather rudimentary - more or less restricted to what I picked up playing "boules" at French camping sites (cf. the first word of my post) - I had abstained from reading the French collector's magazine Figurines. But I should have done so, especially No 30, October 1999. For it contains an article by Rigo, titled "J'etait à Yorktown". The author has made use of almost all available French sources. To neglect it before turning to the topic "The French in the American Revolutionary War", deserves punishment. And punished I was!
I scraped together my few French words and phrases, profited of my knowledge of English (as one third of the English vocabulary is of French origin, thanks to the Normans), and consulted my wife who speaks French fluently, and learned from this article that the regiment de Gâtinois were wearing the old 1776 regulation uniforms, with yellow turn-down collars, and violet cuffs, lapels and turn-backs. So I had to re-do my regiment, which was a rather tricky affair as I had based it in groups of four, and had to get at the interior cuffs and lapels which I had painted white with violet piping before. With the collars I couldn't do much, as the Front Rank figures have got stand-up collars. I was lucky enough that I had incorrectly painted them yellow before.
Furthermore, the Gâtinois regiment were still wearing their old-fashioned laced hats at Yorktown as they hadn't had the chance to change their uniforms, serving in the Caribbean. So I had to add the silver and "false-silver" laces to their headgear. The "false-silver" of the rank-and-file hats I tried to imitate by painting them white, adding a brush of silver at the upper corner ("false-silver" was a lace, woven of white and silver tread).
I also learned that the cords on the flags were not golden, but were twined of black and violet silk strings, the colours of the regimental flag. And I was told that French flags of this period didn't have fringes - whatever TV and films try to tell you. So I had to cut off the fringes I had so meticulously produced before!