Inquiring minds want to know. I assume its neutral refs if its different conferences, but what if its two teams from the same.
The CFP Committee administers the CFP Playoff, not the Conferences. Officiating Crews assigned by CFP. They use crews from all Conferences but use a crew that has no affiliation to Conference of either team playing (no different than they've done in CFP Bowls including 4-Team Invitational CFP Games).