An interesting item from Don Troiani’s book, “Military Buttons of the American Revolution”; due to the general lack of supplies throughout the war, American soldiers would sometimes wear British uniforms that were captured. Often these were captured as part of a captured ship’s cargo, and hence would be in a sizeable volume due for British soldiers stationed in America.
When time and resources would allow, the uniforms would be taken apart, dyed brown or a color deemed fitting by the regiment that would wear them, and then sewn back together and issued to the soldiers. In other cases the uniforms would be issued as-is, in their original British colors.
The buttons would often be left on, and so it’s very possible that some of the British regimental buttons dug from battle and camp sites might have actually been worn at some point by an American soldier. Interesting!