There are a group of United Stated Civil War soldiers from the union that had a quite different uniform. From pictures in books and movies they were loose and red. Their pants were what could you say? Puffy! It really stood out. What was their story? Were they an elite unit or just specific to something? Thank you historians!
I’m almost certain you’re talking about Zouaves, who get a brief mention in this old answer from u/dandan_noodles. Check it out while we wait for a more specific answer.