One of the units that is now complete is the 2nd Maryland Regiment. Half the figures are by Minifigs, the other half are by Jeff Valent miniatures. The figures are fairly compatible --for example, cartridge boxes and cocked hats are of about equivalent dimensions. However, the Minifigs are more robust, and these figures' muskets (especially the bayonets) are noticeably larger. I may yet trim back the Minifigs' bayonets to reduce the differences.
One of the other units I’m currently working on is Lee’s Legion. The figures were painted green based on a comment their commander (Henry Lee) made about their uniforms while they served in the northern theater. The figures are dismounted dragoons by Freikorps and Peter Pig Miniatures, but I will be using them to represent Lee’s infantry companies. They are such lovely metal figures that I had to find some use for them.
This unit is thought to have changed to light-colored coats with green facings late in the war, as evidenced by the following portrait of Lieutenant-Colonel Henry Lee.
When I started painting the figures I was working under the assumption that the green uniforms were in use for most of the time the regiment was in service. Then I recently read the following description of Lee’s men in John Robert Shaw’s memoir. Shaw was a soldier in the British 33rd Regiment, and he was captured by some of Lee’s men in early March, 1781.
“Scarcely had we gone half way up the lane, when seven of Lee’s light horse made their appearance: my companion swore there was Tarleton’s light horse coming, and, says he, ‘we shall be taken up on suspicion of plundering, and get 500 lashes a piece.’ ‘No;’ said I, upon observing their brown coats, and white cockades, ‘no, friend, you are deceived; these must be the rebels.’ Having therefore discovered his mistake, he began to cry;--but for my part, I thought it very good fortune.—As they were advancing towards us, we concluded to go and meet them; which we accordingly did, and falling on our knees begged for quarter; which they granted us…” 
Based on this description, I think I will repaint the units' coats a whitish brown.  It's an annoyance to catch this only when the figures were so close to completion, but better now, I suppose, than after the figures are varnished.
1. Source: The Life and Travels of John Robert Shaw (1807/1930).
Also on the subject of clothing, Shaw wrote that after he was captured, a rifle officer ordered Shaw and his companion to strip: “…the officer drew his sword and swore, if we did not comply, he would run us through. So they took our clothes, not leaving us even our leggings or shoes; and God knows, they wanted them badly; for such ragged mortals I never saw in my life before, to pass under the character of soldiers.”
2. The description, of course, applies to the mounted portion of Lee’s Legion. To the best of my knowledge, it’s uncertain whether Lee’s infantry also adopted this look, or wore blue coats, like other Continental infantry, or wore something else entirely.