I found this...
The Coptic Legion (Légion Copte / Légion Cophte) was part of the French infantry, and their uniform was indistinguishable from the uniform of French infantry except in colour.
The Coptic troops wore a bicorne made from sheep’s hide leather, and dyed black, with a red horse-hair plume falling from it; and possibly the tricolour cockade fixed to its left side, as all troops in the French Armee d’Orient were required to wear.
They wore yellow trousers made of unbleached linen, and short (calf-length) gaiters of either black or white colour, along with black boots.
They wore a white waistcoat, and over this a green (Dartmouth green) coat that was to buttoned straight down the front. The coat’s collar was either red or yellow; while its cuffs were yellow. The epaulets were red.
They each had a cow-hide knapsack with black straps to contrast with the habit-veste.
I also sourced a few images of these troops, along with one showing the Greek Legion as well. One of the images shows contradictory white straps.