When the System.Windows.SystemParameters.HighContrast property is true or the System.Windows.SystemColors.ControlColor and System.Windows.SystemColors.ControlTextColor are black and white, the system is considered to be in high contrast mode. When in high contrast mode, the IsInHighContrastMode will be set to true and the theme of the XamRibbon is changed to utilize the system colors for accessibility purposes.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, 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