I was sitting in a restaurant by a window. I saw a group of a dozen people walking down the sidewalk. They were all wearing a black out, the exact same outfit. Now, it turns out that I recognized their outfits and realized they were Amish, but I will not soon forget the fear I had to see a dozen black-clad people walking in a tight formation and a steady pace down the sidewalk right in front of me.
I can't help but remark at how disturbing identical uniforms are. We see them in movies and other stories enough and think nothing of them. They are generic pawns. But to see them in real life is creepy. It's individuals, stripped of their individuality.
But when you are somebody in a uniform, it is not that at all. It becomes individuals in character or individuals playing dress-up. It's like, despite all dressing the same, they are their own people. Although some people do have a sense of camaraderie, others are linked by nothing more than their clothes.
Uniforms are an interesting tool to play with. It is certainly easier to do in a visual medium, but not impossible. In prose, you either gloss over them or focus on their differences. Still, though, that is one of the angles to explore: the differences within the uniforms (and people wearing them). Other angles may include individuality within the uniform, power of the uniform, weakness of the uniform, uniform versus uniform, uniform versus non-uniform, and so on.
A lot can be done just by playing with any one of those. Now go out and do it.