How can i be emo with a strict school dress code?

You don't 'do' anything ...except suck it up and wear the damn uniform. I was metal freak during my school days and wore only black, but still had to wear my royal blue and lemon uniform (yes lemon!!) School is school, you are there to learn and better yourself, what you look like should be the last of your concerns. Just Emo it up at the weekends and in the holidays.