Why are some learners red in the roster?

Ever notice some learners show red in the roster or courses appear in red text in the task list and wonder why?

While there are visible due dates in both spots, the red text color is just a quick visual way to see that a learner or course is overdue. 

Looking at their My Task list, learners can see at a glance course that are overdue. 

In the roster, this will appear too for learners who are past their due date.