The xrefresh(1) utility is a simple X program that causes
all or part of your screen to be repainted. This is useful when
system messages have messed up your screen. The xrefresh(1)
utility maps a window on top of the specified area of the screen,
and then immediately unmaps it, causing refresh events to be sent
to all applications. By default, a window with no background is
used, causing all applications to repaint "smoothly." You can,
however, use the various options to indicate that a solid
background (of any color) or the root window background should be
used instead.
Use a black background (in effect, turning off all of the
electron guns to the tube). This can be somewhat disorienting
because everything goes black for a moment.
-displaydisplay
This argument allows you to specify the server and screen to
refresh; see X(5).
-geometryWxH+X+Y
Specifies the portion of the screen to be repainted; see
X(5).
-none
This is the default. All of the windows simply repaint.
-root
Use the root window background.
-solidcolor
Use a solid background of the specified color. Try green.
-white
Use a white background. The screen appears to flash quickly,
and then repaint.