Hi wolfgang, and thanks for your reply.
Wolfgang Schuster
Make a complete (with text) example where we can see your problem (a example of the output could help), I get a red background for the left margin.
Here it is. And the output (processed with texexec --lua) is attached. Thanks for everything. -AJ \setuppapersize [A5][A4] \setuparranging [2UP,rotated,doublesided] \setuplayout [margin=18mm, width=middle,height=middle, topspace=0cm,backspace=18mm] \setupcolors [state=start] \setupbackgrounds [text] [leftmargin] [background=color,backgroundcolor=red] \showframe \showgrid \enableregime[utf] \starttext \section{my taylor is rich} knuthknuth \page[yes] \section{God save the Queen} knuthknuth \stoptext