The Hill Memorial Library at LSU in Baton Rouge has copies of rosters for hundreds of UCV camps. Three of us went there in 2012. We spent two days and had some success searching through folders of UCV Camps in specific counties. We were trying to identify members who served in the 35th Texas Cavalry. They have boxes of rosters in numerical order by camp number, but I not remember if it included other states. You could call them and ask.
The rosters have a column for name, unit, rank, address, but no mention of race. UCV members were supposed to write about their CW experiences. We were not allowed to go through these boxes because they had not been organized and logged into the library system. The library was trying to get the money to hire grad students to perform this chore. If these reminiscences are available today, that might give you the information you are looking for.
I also have a digital 1896 copy of "Organization of 850 UCV Camps" prepared for the 6th reunion and meeting of the association held in Richmond. The camps are listed in numerical order for all states.