Residential College Selection/Traditions

Hey yall I’m a recent ‘30 admit and am really intrigued by the residential college system. I read online that the residential colleges are randomly selected, but a website I was on also mentioned an interest form as part of your selection. Is the interests/lifestyle form that’s being referred to just for roommate matching? I’m also curious besides the obvious aspects of location, name, banner what really differentiates the colleges from one another? Do certain residential colleges have different resources / rooms (like one has a dance studio or something) that others don’t have? Are there lots of college based traditions and activity nights? Just curious!