Here are a couple of books which will help. I do not have them but I am told they are informative.
Alan K. Sumrall, BATTLE FLAGS OF TEXANS IN THE CONFEDERACY, Full color
photos of Texas battleflags . Austin, TX: Eakin Press, 1995
Thomas Reid, PARTAN BAND: BURNETT’S 13TH TEXAS CAVALRY IN THE CIVIL WAR. Denton, TX: University of North Texas Press, 2005