\setuppapersize[A4][A4]
\setuplayout[leftmargin=6cm,rightmargin=10cm]
\showframe
\starttext
\ConTeXt\space\contextversion\blank
before the \type{\starttext}:\crlf
\type{\setuplayout[leftmargin=6cm,rightmargin=10cm]}\crlf
make no difference in displayed frame
\showlayout
\stoptext
