Thank you for the additional information.
Cross’ book has some issues, primarily he was a little sloppy with his research and citations. For example, his citation for his statement that Powell was black is an article by Junius Kimble, Company A, that appeared in Confederate Veteran Magazine (Vol. XVIII, No 10, Oct. 1910, Page 460). However, that article makes no reference at all to the 14th's color bearers. In reality, Cross’ description is a paraphrase of Mockbee’s account found in his writing, Historical Sketch of the 14th Tenn. Regt. of Infantry C.S.A. 1861-1865. Yet Mockbee’s account makes no reference to Powell’s race. Cross also completely ignored Mockbee mentioning Boney Smith who carried the colors after Powell.
Mockbee’s wrote an additional account of Pickett’s Charge, which appeared in the Richmond Times-Dispatch, April 3, 1910, p. 3 (which Cross does not appear to have consulted). It also makes no reference to any black color bearer. This article also mentions that Boney Smith survived the charge and did not go down in a hail of lead as many books claim, and that there was an additional color bearer after Smith. Smith was the last color bearer Mockbee saw, but William P. Davis, Company K, told Mockbee that Drew Marshall was the last person carrying the colors after Mockbee had retreated.
There is also a claim that Mockbee described Boney Smith as a "colored guard," which seems to go back to a book entitled Into the Fight – Pickett's Charge at Gettysburg, by John Michael Priest. However, when I spoke to Mr. Priest about that claim, he very freely admitted that he no longer believed it to be true. He stated that he was working off of a prepared transcript of Mockbee’s writing and not the handwritten text. The prepared transcript clearly mentioned a "colored guard." However, once he saw the handwritten account he readily admitted that it described a "color guard." Having seen a copy of the handwritten account myself, it is so clear that I wonder how the mistake was made in the first place. It very clearly says "color," not colored.
I also discussed this with John Coski, the principal transcriber of the most recent and probably the most accurate transcription of Mockbee's Historical Sketch. He dismissed the claims that it describes a black color bearer as "a case of ‘Black Confederate’ wishful thinking." The fact is there is zero firsthand documentation to support that a black color bearer carried the flag at Gettysburg. Neither the accounts by men of the 14th Tennessee nor the 14th Connecticut, who captured it, mention a black color bearer. That is why I was interested in when George Johnson reportedly carried the flag and the documentation supporting it.
I do thank you for the leads and perhaps I’ll follow up with Dr. Bradley directly.