I am surprised there are Black people in Nebraska to begin with (that is a little joke I tell someone I know from Omaha).
All I will say is our state does the assigning from the IHSA Office by the administrator of that sport (one for Boy's and one for Girl's Basketball). They have a lot of things they consider from a Power Rating to where you live. And they do make an effort for diversity as our teams are very diverse. It would look silly if you had all white officials and none of the coaches or players looked like the officials. I am going to assume that might not be as much of an issue in all of Nebraska.
Peace