Would not look great walking around a campus of CG uniforms wearing something totally different.
It is more than that - remember, there are other SA exchange students on campus, so a different uniform is not uncommon. However, I have witnessed bizarre situations where a candidate, or plebe upon arrival was under a misguided impression that their prior JROTC or CAP rank actually mattered as a incoming freshman at the school. I literally heard a new plebe/swab/4* say to an upperclassman "I am a Cadet Colonel, and you will address me as such..."
Yeah.... that did not go well for him and it stuck with him the entire year. In that moment, every other freshman was granted a reprieve as the upperclassman swarmed this poor guy and spent a few minutes of many-to-one personal time with the misguided individual.
Remember, if you are part of Bear Day, CFAD, or Genesis - you have passed round 1 of the screening. You are a stellar student and likely have a candidate resume that rivals the likes of those who have already been appointed and enrolled into the school. So as not to confuse anyone about your thoughts behind the importance of JROTC/CAP uniforms/ranks/awards.... just be a nice and respectful high school student that is wearing something conservative, weather appropriate, and worthy of someone interviewing for a multi-hundred-thousand dollar scholarship. As
@Korab mentioned, khakis and a button down shirt would be appropriate and not stand out in a bad way. As you will learn, the key to your first year will be to blend in with your classmates.