The value of the opacity of the Visual is expressed as a value between 0 and 1. A value of 0 indicates that the element is completely transparent, whereas a value of 1 indicates that the element is completely opaque. A value of 0.5 indicates that the element is 50 percent opaque. Values that are less than 0 are treated as 0; values that are greater than 1 are treated as 1.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)