Active window title bar color. If the gradient effect is enabled, specifies the left side color in the color gradient of an active window's title bar.
First available in version 3.0 build 2039.
The color is represented as a 6 character hexadecimal value.
This variable is automatically updated whenever there is a change to the system color settings.
Windows NT and Windows 95: These versions of Windows do not have an option to display a gradient effect.