Parents, would you be mad if this happened to your kid?

Im a junior in highschool and i never do anything wrong, ive never gotten a dentention ect. Well one morning i wasn't thinking and put on sweatpants which i usually don't wear to school The rule at my school is you can wear sweatpants only on friday, and they need to be school colors (marron, grey, or black) mine were blue So my math teacher gave me a warning because she said i dont break the dress code. so i said okay thats fine i just forgot about that rule. so the weekend pes and that monday i get a dentention for it, my homeroom teacher said i should talk to the principal about it because she said to that i dont break the dress code and should get a warning. So, i go and talk to the principal and i say "I'm sorry i forgot can i just get a warning?" and just as im sitting down he throws the detention back in my face and says "theres your warning, we've made annoucnments about this but you probably didnt hear because of your absense" ive been asbent because i hurt my leg and my gr