Not really. Matriculation is the moment when you sign the big shiny (very old!) book which formally makes you a member of your college. Until you die (
). Needless to say, it's taken pretty seriously and at best you'd look very out of place without a tie - at worst, you'd look disorganised (forgot to pack one) or disrespectful for not adhering to the dress code.
Sorry. But the very formal occasions are few and far between, so it's not that bad really. The whole thing takes about an hour and a half from start to finish anyway (including the photo), so it's not like being back at school.