[NTG-context] gnuplot module: `option=monochrome` does not work.

Dear ConTeXt folks, I want to create monochrome plots, but `option=monochrome` is ignored. \usemodule[gnuplot] \setupGNUPLOT[terminal=context,option=monochrome] \startGNUPLOTscript[pi] plot pi t '$π = \ctxlua{context(math.pi)}$' \stopGNUPLOTscript \starttext \useGNUPLOTgraphic[pi] \blank \CONTEXT\ \contextmark\ \contextversion \stoptext Is that the correct way to enable monochrome output? Looking at the Wiki page [1] it should be something like the above. Am I doing something wrong? Thanks, Paul [1] http://wiki.contextgarden.net/Gnuplot