At least when I was in, we were "supposed to" have uniforms, but they were never provided to all of us. Just navy shorts and a light blue tucked-in t-shirt with the sea org logo was what it consisted of, I think. Black, flat nylon cord belt with silver buckle to complete the look. Nothing fancy or elaborate. Only when you actually joined the SO did you really start having to wear the clothes.
My memory's a little bit hazy, but that's what I remember. I don't think I ever got one.