Re: Line under taskbar icons

I find those underlines extremely annoying. Just when I think I've completely closed a program or an app...

Nobody told us what those underlines even mean. Why they differ in color and length on open apps.

I've been IT savvy for about 15 years and feel as informed about this particular issue as a lab rat right now. Even Google doesn't give any sound results. 

Microsoft, y u bully?