No luck on his race. I've researched a man from my home county in east Tennessee that was probably conscripted into Company B 19th TN infantry. He deserted after fighting at Chickamauga, came back to Tennessee and joined the Union 4th TN Infantry. He's listed as "Mulatto" in the 1860 census. In subsequent census and even on his death certificate he's listed as "white", even though he's described with a "dark complexion" on the Union Army descriptive roll. I'm guessing Captain Jones was light-skinned enough to pass for white ???
I did notice this from the article you posted a link to : "By the end of the war, a great many were no longer living because of the hardships they endured," Motz-Frazier said. "Matt Blue - you know, who had a homestead here in Carthage - was one of the 600. At the end of the war, when the war was over and they opened up the prison camp for men to come home, Matt Blue could not walk, he was so ill. Mr. Jones hired a carriage for him - and some other Carthage men - to come home."
There was a Private Malcom Blue in Co.C 35th NC from Moore County. He was captured at Five Forks and sent to Hart's Island, NY. Took the oath on 6/18/1865. My paternal 2nd great-grandfather in the 13th NC was captured the next day and also sent there. He took the oath on 6/19/1865. The Federals provided rail transportation as close to their home as they could get them. My relative was brought as close as Wilkesboro. He was from the mountains in Wilkes/Caldwell Counties. Private Blue was probably too sick to travel all the way home from wherever they dropped him off, so his old Lieutenant sent a buggy for him. (I can find no record of him ever being promoted to Colonel, he enrolled as a 3rd Lieutenant).