<number id="ncolors" type="slider" arg="-ncolors %"
_label="Number of colors" _low-label="Two" _high-label="Many"
low="1" high="255" default="255"/>
<number id="ncolors" type="slider" arg="-ncolors %"
_label="Number of colors" _low-label="Two" _high-label="Many"
low="1" high="255" default="255"/>