The Classic UI has a field called "Is Late", in the Tasks module as shown in the screenshot below. How is the colour of this field determined?
All supported clarity releases
The "Is Late" field always relies on the Baseline. This field will not be accurate if there are no Baselines defined.
It is set to Green if the Task Finish Date is equal to or less than the Baseline Finish Date.
It is set to Red if the Task Finish Date is greater than the Baseline Finish Date.
It is not dependent on the Task Status either.