I recently purchased Bleeding Blue and Gray: Civil War Surgery and the Evolution of American Medicine by Ira M. Rutkow (2005). On page 12:
Poised at the foot of Henry House Hill, the Eleventh New York Infantry, best known as the First Fire Zouaves, may never have seen Johnston’s troops as they gathered at the ridge’s crest, but Johnston’s men could not miss the Yankees. Advancing up the slope, the 950 or so Northerners were a colorful lot. Sporting dark blue waistcoats accented in red and gold trim, bright red blouses, flowing crimson bloomers with blue piping and white spats, all capped off by a red fez, these warriors were the height of mid-nineteenth-century military haute couture.
Double Yoi. I’d tell you what Rutkow’s source for this description is, but he neglected to note it.
I know, I go on and on about the uniform of the 11th NY Fire Zouaves at Bull Run, including here, here, here, and here. To recap, despite numerous, even eyewitness accounts to the contrary, the regiment’s enlisted men did not wear red pants during the battle. In fact, at no time were red pants ever a part of their uniform, though officers wore red pants of the chasseur pattern. But don’t take my word for it:
Above is a photo of the 11th NY Zouave uniform of Private Francis E. Brownell of Company A, on display at Manassas National Battlefield (thanks to Jim Burgess at the park). Notice the color (gray-blue), the name of Brownell’s New York fire company on his belt, and his red fireman’s jersey. This is the same uniform Brownell was wearing on May 23rd, 1861, when he accompanied his colonel Elmer Ellsworth into Alexandria’s Marshall House hotel to pull down a secession banner flying from the building and visible through a glass from the White House. As Ellsworth descended the stairs with the flag he was killed by a shotgun blast fired by the hotel’s proprietor, James Jackson. Brownell, who was with Ellsworth, quickly shot Jackson in the face, then drove his saber bayonet through his body.
Ellsworth became a dead hero in the North, mourned by his friend Abraham Lincoln. Jackson received similar posthumous honors in the south. Brownell became a living celebrity, whose photo, complete with Ellsworth’s blood stained banner, became a popular item.
Brownell left the unit before First Bull Run, accepting a commission in the 11th US Infantry, and in 1877 he was awarded the Medal of Honor for his action at the Marshall House. You’ll find his death notice here.
As you can read on this great website on the 11th, the regiment’s worn-out, gray-blue Zouave uniforms were grudgingly exchanged for standard union blue jackets and pants before First Manassas. Many men continued to wear their distinctive red firemen’s shirts, and some may have worn red fezes, though the official uniform headgear as seen with Brownell was a kepi with company insignia and “1Z” for First Zouaves. I think this image of the regiment fighting alongside the 69th New York Militia probably gives a good idea of what they looked like on the field at First Bull Run.