Which Confederate units were dressed in blue at the First Battle of Bull Run?

At the First Battle of Bull Run, the 11th Mississippi Infantry and the 1st Louisiana Infantry were among the Confederate units that wore blue uniforms. These units were dressed in blue due to a combination of pre-war purchases and availability of fabric, which led to a mix-up with the traditional gray uniforms typically associated with Confederate forces. As a result, the blue-clad soldiers contributed to the confusion on the battlefield, especially for Union troops.