I wore uniforms for 12 years of school. The boys wore uniforms 1st -8th grade, and had to wear a jacket and tie in high school.
We always found a way to express our individualism.
Might not seem like much, but for the girls, it was all about shoes, and the vests and sweaters of our choice we were allowed to wear under our school jacket. This was in the 70's when sweater vests were really in.
Since we all were wearing the same color, there was an unwritten law that you could wear ANY color vest you wanted, whether it matched the uniform or not.
I know some girls hated it, but I never minded.
I don't know which came first, the chicken or the egg, but I've never really cared that much about having an extensive wardrobe of a bunch of different looks. If you have me a dozen pairs of pants, all the same except for the colors, and a bunch of shirts that have a few different styles, but different colors for each, I'd be perfectly happy.
Was it becasue I wore the uniform and got used to it, or didn't like clothes so liked the simplicity of a uniform?
As far as the boys, I feel it made them a lot more comfortable in situations where they would have to be dressed professionally.