SwimOffice Admin - Super User or Lesson Admin - Full Access

Why are some of my Instructor names red in the Heat Map?

A red name indicates they are assigned to two or more instances of the same time slot. In the first example below, it's easy to see how Andrea S. is assigned to two different slots, both for 7:00 pm on the same day.
Heat Map conflict, same class

In the second example, although all three instructors are booked for the same time in all three classes, those classes are during three different weeks, so why they show as red at first appears to be a mystery.
Heat Map conflict, different classes

However, as we continue scrolling down, we see a class that spans the entire time frame of the first three classes, and thus the conflict and red names.
Heat Map conflict, spanning all classes

It's up to you if you choose to resolve the conflicts. TULessons allows you to double book slots, as there may be times you allow different types of students in different classes but during the same time slots for the same instructors.

See Also
What is a Heat Map?