If they, (free Black or Mulatto) were on the muster roll, and ranked, (at least a Private) had a specific duty they were expected to preform, I expect they were paid and considered soldiers. Slaves weren't paid. Body Servants or Body Guards came to the war with their masters and weren't paid. They later had the opportunity to apply for a "Colored Man's Pension." (this is what they were called in Tennessee.)

In 1864 Union General August Kautz's, wrote the following in ”Customs of Service, for Non-Commissioned Officers and Soldiers."

"In the fullest sense, any man in the military service who receives pay, whether sworn in or not, is a soldier, because he is subject to military law. Under this general head, laborers, teamsters, sutlers, chaplains, &c. are soldiers. In a more limited sense, a private soldier is a man enlisted in the military service to serve in the cavalry, artillery, or infantry. He is said to be enlisted when he has been examined, his duties of obedience explained to him, and after he has taken the prescribed oath."

Why wouldn't this apply to a Confederate Soldier, regardless of race, creed, or color ????