\setuphead[Topic] [textcommand=\doTitle] \def\doTitle#1{% \bgroup \setupframed [offset=0.3ex,linewidth=2pt,framecolor=red]
^^^^^^^^^^^^ use that one with care since framed is used all over the place in context, better pass these settings to \framed directly or create a framed (\defineframed)
\framed{\blue \ss #1}% \egroup% }
But the linewidth as no effect (it is not in the documented \setuphead options, but a just try it.
rulethickness=2pt
Also, is it possible to set the linestyle to "daashed" or something like that?
\startuniqueMPgraphic{dashed} draw OverlayBox dashed evenly ; \stopuniqueMPgraphic
\defineoverlay[dashed][\uniqueMPgraphic{dashed}]
\framed[background=dashed]{I didn't test this}
I would not have expected differently than that this works! If you use this mechanism, the frame will have to be set to off. If you still want to change the thickness of the dashed box you will do this in the Metapost code. Then it will be time to consult the Metafun manual ;-) \startuniqueMPgraphic{dashed} pickup pencircle scaled 2pt draw OverlayBox dashed evenly ; \stopuniqueMPgraphic Willi