\environment pagecolumns-000

\definepagecolumns
  [example]
  [n=3,
   distance=\emwidth]

\setupbackgrounds
  [text]
  [background=color,
   backgroundcolor=color-1]

\starttext

\startpagecolumns[example]

\dorecurse {20} {
  HERE #1.1
  \samplefile{klein}\column
  \samplefile{klein}\page
}

\page[right]

RIGHT PAGE

\page[left]

LEFT PAGE

\dorecurse {20} {
  HERE #1.2
  \samplefile{klein}\column
  \samplefile{klein}\page
}

\stoppagecolumns

\stoptext