Several blacks (mulattoes) posed as whites and served in state regiments, some as officers. George and Stafford Grimes of Caroline County enlisted with the Fredericksburg Artillery in 1862, though both later deserted. George was recaptured and plans were made to court-martial him for desertion. However the court decided against this because as a “Negro” he could not be a soldier nor tried as one.
http://cwmemory.com/2011/03/06/ervin-jordans-black-confederates-part-2/