I'm aware of at least three Confederate "Free Men Of Color" that actually fought at Gettysburg :
Charles Lutz Company F 8th Mississippi was wounded and captured, later exchanged. He was again wounded in 1864 resulting in his right arm being amputated. He, and later his widow drew pensions
William Colen Revels, Musician in Co.H 21st NC was wounded at Gettysburg. His record also shows him wounded at New Bern, NC. and at Winchester, Virginia. One of the first Volunteers of any color from Surry County, NC.
In the same regiment was a John W. Venable, whose widow applied for a pension in 1929. It was disallowed with the notation : "Colored Woman, no law for this". One of his comrades tried to help, writing the pension board, John Sawyer, also a veteran of Co.H 21st Infantry “made his mark” on a deposition, stating he “was well acquainted with John Venable (colored) who was in Company H, 21st Regiment, that he was honorably discharged from service, and made a good soldier, and his widow is entitled to a pension.”
There are several accounts of a Black Color-Bearer with the 14th Tennessee killed during Pickett's Charge. Only his nickname is remembered as "Bony Smith" some accounts say he was an enlisted soldier, others that he was someone's "Body-Servant".
Levi Miller, a Body-Servant with the 5th Texas, claimed that relatives of his that had escaped slavery to Pennsylvania , tried to get him to do the same, but he refused.