The valid range of values for this property are from 0 to 255, inclusive. A value of 0 indicates the tooltip is completely transparent; 255, completely opaque. Changing the BackColor property value also updates the AlphaLevel.
Developers should use the PE property instead of the individual color properties, as the PaintElement class offers superior shading and texturing capabilities.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2