Hi,
Strange behavior: why is the colored text ?

Thanks,

Fabrice

\usemodule[tikz]

\startuniqueMPgraphic{titled}
path p ;
p := unitsquare xscaled OverlayWidth yscaled OverlayHeight ;
pickup pencircle scaled 1mm ;
drawoptions(withcolor .625yellow) ;
draw llcorner p--lrcorner p ;
setbounds currentpicture to p ;
\stopuniqueMPgraphic

\defineoverlay[titled][\uniqueMPgraphic{titled}]

\define[2]\ChapterCommand
  {\setbox\scratchbox\hbox to \leftmarginwidth{#1\hss}%
   \hskip-\dimexpr\leftmarginwidth+\leftmargindistance\relax
   \framed
     [background=titled,frame=off,offset=0pt]
     {\box\scratchbox
      \hskip\leftmargindistance
      #2}}

\setuphead
  [chapter]
  [command=\ChapterCommand,
   textstyle=\ss,
   color=darkred,
   conversion=Characters]

\setuphead
  [section]
  [command=\ChapterCommand,
   textstyle=\ss,
   color=darkred,
   sectionsegments=section:section]

\starttext

\startchapter
  [title={Activités d'approche}]

\startsection
  [title={Sans carreaux}]

\placefigure[right,none]{}
{
\hbox{
\starttikzpicture[>=stealth,scale=0.8]
\draw [->,color=blue,ultra thick] (0,0)--(5,2);
\draw [->,color=green,ultra thick] (6,1.5)--(5,0);
\draw [->,color=red,ultra thick] (4,-0.8)--(2,-0.1);
\draw [color=blue](2.5,1)     node[above] {$\vec{u}$};
\draw [color=green](5.5,0.75) node[right] {$\vec{v}$};
\draw [,color=red](3,-0.45)   node[above] {$\vec{w}$};
\node (A) at (0.5,-0.5) {A};
\node [above right] at (A) {$\times$};
\stoptikzpicture}}
\startitemize[n][stopper={)},style=bold]
On a tracé trois vecteurs et placé un point A sur la figure ci-contre.
\startitemize[a][stopper={)},style=bold]
\item Construire le point C tel que $\vec{\rm{AC}}=\vec{u} + \vec{v}$.
\item Construire le point B tel que  $\vec{\rm{AB}}=\vec{u} + \vec{v} + \vec{w} $.
\stopitemize
\stopitemize

\stopsection

\stopchapter
\stoptext