In my experience when a person makes remarks about your appearance (clothing, hair, ect) it shows that they may be feeling as uncomfortable as you are. Appearance is the first thing people notice so any comments about a jean jacket or an unkempt head of hair shouldn't be taken too seriously. It's probably just a weak attempt at some small talk.
This is all coming from someone with little or no sense of style btw... so feel free to disregard this.
Im going back to school soon myself, so a haircut may be in order. I wonder where i left my weedwhacker.