Colleges, especially large ones, do have tons of students of different faiths, but I felt contacts were still minimal. My randomly-assigned freshman year room-mate was a devout Christian and would sing in worship - super wonderful guy. But after that, not much. It's so easy to just hang out with people similar to you - at all stages of life.
Even when you meet someone of a certain faith, you're likely to experience that interaction through holiday, festival, food, dress and so on - think asking a Muslim about Ramadan or being invited to a Hanukah party - but you're not likely to ask doctrinal or theological questions.