Here goes the memory test again!
The main difference would be the length of the habit, or coat. That was consistent for the length of time these units existed.
The middle guard was usually considered to be the two-battailon Fusilier-Grenadiers and two-battalion Fusilier-Chasseurs.
The grenadiers wore the square-lapelled Old Guard Grenadier coat, but with white fringed epaulettes, sometimes with red crescents, sometimes with red stripes on the white shoulder board. They also had gaiters reaching above the knee as did the Old Guard Grenadiers and Chasseurs. They wore a shako with white chevrons on the side, long scarlet plumes on the front.
The chasseurs wore pointed lapels, as the Old Guard Chasseurs. Red fringed and crescent epaulettes, green shoulder boards. Gaiters above the knee. Shako, no chevrons, green plume tipped red.
The young guard Tirailleur-Grenadiers wore the short light infantry cut-away coat over white vests, dark blue lapels, red pointed cuffs tipped white. Red shoulder flaps edged white. Gaiters were short, below the knee. Shakos with scarlet plume, and I think white chevrons on the side. I personally conside this the handsomest French uniform of the period.
The young guard Voltigeurs wore same light infantry coat, yellow or buff collar (Old Guard Chasseurs and Fusilier Chasseurs had dark blue collars). I draw a blank on the fringed epaulettes, but do NOT recall them being a green shoulder board, red fringes, red crescent. I seem to recall all green with yellow fringe. Shakos with tall green plumes, yellow tip. No side chevrons. red pointed cuffs edged white. Gaiters Below the knee.
I believe the Dutch Guard Grenadiers may have been considered middle guard, but no other Young Guard regiment wore long-tailed habits.
GdeP
looks at the new U.S.S. Constitution for Black Seas.