gnome-control-center/capplets/screensaver/screensavers/bsod.xml

<?xml version="1.0" encoding="ISO-8859-1"?>

<screensaver name="BSOD">
    <command arg="-root"/>
	<!-- goes from 3 ... INT_MAX -->
    <number id="speed" _label="Speed" _low-label="Slow" _high-label="Fast" 
            type="slider" low="0" high="20003" default="10000" arg="-delay %" 
            from-cli-conv="20000 - var" to-cli-conv="20000 - var"/>
    <select id="use_color">
	<option id="color" _label="Full Color"/>
	<option id="mono" _label="Monochrome" arg-set="-mono" test="mono"/>
    </select>
</screensaver>