VTurnOffTruecolor - turns the truecolor mode off.
VTurnOffTruecolor turns the truecolor mode off. If the visual class is
PseudoColor or DirectColor and truecolor is on, VTurnOffTruecolor turns the
truecolor off, puts the previous colormap contents and reserved colors
stored in a temporary file, resets all background and foreground colors for
all windows, and redraws the content of the button window, dialog window,
title window and menu. If there is any message in the dialog window, it has
to be redrawn by calling VDisplayDialogMessage.
0 - work successfully.
1 - memory allocation error.
236 - truecolor is not on.
If VCreateColormap is not called earlier, VTurnOffTruecolor prints an
error message to the standard error stream, produces a core dump file
and exits from the current process.