I've always been fascinated with the Zouave uniforms a few of the regiments wore during the Civil War. So bright and... different. I think rather than the bright colors, it's the puffy pants that make the uniforms appear as an oddity to some. *BUT* all that aside, units such as the 14th Brooklyn (84th NY) and 114th PA were highly honored units. Very respected, and to be allowed to wear a Zouave uniform meant that you had already been proven as one of the best. French troops fighting in the Middle East wore uniforms like these, and in the Civil War era, anything that had to do with the French military was sought after and highly regarded. Sometimes they even got the material for the uniforms directly from France.
