ToolStrip control never fire Enter/Leave event??

Question

I created a movable panel in WinForms. I use a ToolStrip as a titlebar in the panel. I'll use the ToolStrip to move the panel as well as indicating the panel is "active" or not. So when the panel is active, I want to change the ToolStrip's BackColor to Red.

UPDATE: The panel will host other controls, such as a listview. I want the panel being shown as "active" when the hosted control get focus, kind like the behavior of a normal window, whereas the window becomes the panel, and the titlebar becomes the ToolStrip.

When the panel is considered as "active"

1. hosted control get focus
2. ToolStrip being MouseDown/MouseClick
3. ToolStrip being dragged by mouse

The idea is capturing ToolStrip's Enter/Leave event to change the color, but it seems those events are never fired.

Are those events truly never fired? Should I capture other events?