% example by wolfgang (for marco)

\setuplayout
  [header=4cm]

\setupheadertexts
  [\setups{headlist}]

\startsetups [headlist]
  \framed[align=normal,frame=off]
    {\placelist[chapter][alternative=highlight,criterium=all]}
\stopsetups

\definelistalternative
  [highlight]
  [renderingsetup=list:highlight]

% \doifelse{\fetchmark[chapter][first]}{\currentlistentrytitle} % not expandable so fails
% \doifelse{\fetchmark[chapter][first]}{\ctxcommand{listtitle("\currentlist",\currentlistindex)}} % nasty

\startsetups [list:highlight]
    \par
    \startlinealignment[middle]
    % hh: new trickery: \namesstructureheadlocation
    \ifnum\currentlistentrylocation=\namedstructureheadlocation{chapter}\relax
        \color[red] {\currentlistentrytitle}
    \else
        \color[blue]{\currentlistentrytitle}
    \fi
    \stoplinealignment
    \par
\stopsetups

\setupinteraction
  [state=start,
   color=lightgray,
   contrastcolor=darkgreen]

\starttext
    \startchapter [title=alpha]                    \stopchapter
    \startchapter [title=beta]  \page \input knuth \stopchapter
    \startchapter [title=gamma]                    \stopchapter
\stoptext
