This message specifies a change in one or more system colors. Windows sends the message to all top-level windows when a change is made in the system color setting.
wParam
This parameter is not used.
lParam
This parameter is not used.
Windows sends a WM_PAINT message to any window that is affected by a system color change.
Applications that have brushes that use the existing system colors should delete those brushes and re-create them by using the new system colors.
WM_PAINT