Only when you click on the toolbar button that a a label appears with the button function.. eg. clicking on the black pen toggles "Thin Pen" and "Thick Pen" -After clicking, not just hovering on it.. you must click on it.
* at design time, you can draw over the hot spot box, even if you draw a black box still the hot spot appears 50% transparent, but at run time hot spot becomes completely opaque, and you have to remember where was it
* If you draw the hots pot over a perfect black box, then at runtime you can't see the hot spot and you only see the black box.