I have seen this thread, and not to step on any toes, as I'm a new guy, but all of you are pretty off the mark in terms of French Drummers of this time, I ave been a Seven Yrs War nut for yrs and know a lot about the French Army. That last site, I don't understand it, it's not right,
There are only two versions of Drummers in the entire French Army in this period. The blue coat, red undercloths version of the Kings Liverie, and the reverse colors, Red Coat, blue undercloths version of the queens liverie, none of which are shown in the posts. Let me a couple days to find a good link to a picture of this. No matter the regiment, it has one of these variations for a drummer. Almost every one has the Kings or Blue coat. Actually that photo of the figures above is pretty good, but it isn't very good I think to explain the actual uniform for painting.
Jude