\definetextbackground[one][location=text,     background=color,backgroundcolor=yellow]
\definetextbackground[two][location=paragraph,background=color,backgroundcolor=green]

\starttext

\showframe

\startitemize
\startitem \starttextbackground[one]\input tufte \stoptextbackground \stopitem
\stopitemize

\startnarrower
\starttextbackground[one]\input tufte \stoptextbackground
\stopnarrower

\startnarrower
\starttextbackground[two]\input tufte \stoptextbackground
\stopnarrower

\starttextbackground[two]\startnarrower
\input tufte
\stopnarrower
\stoptextbackground

\stoptext
