Why is the Service Package pink even though the balance is zero?

When you go to Functions-> Services -> View Services some member packages may appear pink.  What does this pink alert mean?

1. If the member has an [open balance] on the package they will have a pink alert.
2. If the member has a [low session count alert] ON, the package will have a pink alert. 

   
The [low session count alert] is set in your [system settings] and determined by you.  Go to: Tools-> System Settings -> Other Settings (near the bottom)-> Edit-> [Service Package Renewal Alert Session Count Trigger].