Here is a simple example of a 'Draft' watermark.
<texcodecontext source=yes mode=mkiv>\setupcolors[state=start]
\defineoverlay[WatermarkOverlay]
[{\framed[frame=off,foregroundcolor=gray]
\starttext
\chapter{firstThe grey Watermark} \dorecurse{30}{input knuth \input knuth \input tufte }knuth
\stoptext
</texcodecontext>[[Category:Sample documents]]