I sit in our club level, and every game there are fans from the opposing teams wearing their team colors and names. Of course, there's nothing offensive about it. Never once have I seen anyone say anything to them about it, nor have I seen them "misbehave". Pulling for their team is expected, as long as they're not obnoxious.
There's a club level policy that if you need to sell your tickets, sell it to another club level member. And don't sell them to opposing fans. But many members have relatives and friends that they'd like to sit with them, and some of those are from the other team. And that's fine. That situation is probably even more pronounced with MSU and OM since the schools are in the same state.
You should have no problems.