\environment columnsets-000

\definecolumnset[example][n=3,page=left]

\definecolumnsetspan[wide][n=2,background=contrast,color=white]

\definecolor[fakerulecolor]

\starttext

\startcolumnset[example]

  \startcolumnsetspan[wide][default=btlr]

    \startsimplecolumns
      \dorecurse{2}{\fakewords{25}{40}\par}
    \stopsimplecolumns

  \stopcolumnsetspan

  \dorecurse{15}{\fakewords{100}{200}\par}

\stopcolumnset

\stoptext