This command creates a GreyOut button. GreyOut buttons are transparent. When clicked, a GreyOut button paints the area beneath it on the slide grey. When you release the mouse, the grey is removed. If the button is place over text of a transparent field, the grey is actually painted behind the text, and the effect is to grey out that text. (If the field is opaque, the grey will be invisibly behind the field, and the effect is lost.)
CAUTION: If there is any portion of a graph, picture, or diagram beneath a GreyOut button, that portion will be erased when the GreyOut button is activated. (Text in a field will not be affected.)