In JDK 9 since b116 we support Taskbar::setWindowProgressState(Taskbar.State), now on Windows only.
The method is used to visually represent a state of progress via small progress bar on top of an application icon in the taskbar.

There are 5 states: OFF, NORMAL, PAUSED, INDETERMINATE, ERROR.
Trying them on my Windows 10 machine, I see ERROR as a red tint on the icon, PAUSED as yellow but OFF, NORMAL, INDETERMINATE states look exactly the same (green) and behave the same (as a determinate bar).

I understand this is work in progress but what's the idea behind these states? Should i.e. NORMAL and INDETERMINATE behave differently? And OFF have some effect? How should I let a user know that the progress is OFF?