As a general rule, openly racist comments are not tolerated. If someone said something offensive, people would pull them up on it immediately, and they would soon run out of friends. That's not to say that no-one at university ever holds any racist views, but they will more likely be expressed in private.
A different matter entirely is whether people tend to group together with other people who speak the same language as them. Whilst this is unfortunate if it removes all form of interaction with other races, I think its both understandable and inevitable.
Whether there is a large degree of self segregation within language groups along race lines is not so clear cut. If the group is a distinct minority then this is understandable, or it may just be that people of the same race happen to share the same interests.