HKCU\Control Panel\
The Colors subkey contains entries that determine the color of each element of the Windows 2000 desktop. The values are shown as a series of three numbers, which refer to the RGB (red-green-blue) value of the color.
To change the colors of the elements of the Windows 2000 desktop, double-click Display in Control Panel, and then click the Appearance tab in the Display Properties dialog box.
Changes made using the Display Properties dialog box are effective immediately; changes made using the registry are not effective until the computer has been restarted.