MahApps/MahApps.Metro — pull request #1017 by grokys (2014-02-06 12:30:29+00:00)
Title: Make validation popup transparent on mouseover.

The validation popup can mask adjacent controls. This pull request makes the validation popup partially transparent when the mouse is over. I would also like to make it so clicks to a control under the validation popup are routed to that control. Unfortunately setting IsHitTestVisible=false on the control also prevents IsMouseOver changing. Any idea how to achieve this?