Jim,

From my website:-

"Fournet’s command ultimately received the official designation 10th Louisiana Infantry Battalion, but it was more commonly known by its nickname, the Yellow Jackets Battalion. While it sounds as if the nickname derived from the wasp like insect known for its vicious sting, that was not the case at all. In a letter written after the war a former officer of the battalion, explained. it received the name of Yellow Jackets Battalion as most of the men were dressed with home made yellow cottonade suits.

"Louisianians in the Civil War" By Lawrence L. Hewitt.
YELLOW JACKETS BATTALION - Arthur W. Bergeron Jr. Page 51"

http://confederateuniforms.org/conun/earlywaruniforms-la01.php

Aso:-

"From Bergeron, "Yellow Jackets," 2:

"Fournet's command ultimately received the official designation 10th Louisiana Infantry Battalion, but it was more commonly known by its nickname, the Yellow Jackets Battalion. While it sounds as if the nickname derived from the wasp-like insect known for its vicious sting, that was not the case at all. In a letter written after the war, a former officer of the battalion [MAJ Arthur SIMON] explained, '... It received the name of Yellow Jackets Battalion as most of the men were dressed with home made yellow cottonade suits. ...'""

http://www.acadiansingray.com/Yellow%20Jacket%20(10th)%20Bn.%20Inf.htm

Alan Thrower
England