[NTG-context] \em producing red text?

In some overheads I'm creating, I'd like emphasized text {\em like this} to appear as red. I hoped that something like this would work: \setupbodyfontenvironment[default][em={slanted, textcolor=red}] but it doesn't. What is the canonical way of obtaining red, emphasized, text? Thanks, Alasdair -- Blog: http://amca01.wordpress.com Web: http://sites.google.com/site/amca01/ Facebook: http://www.facebook.com/alasdair.mcandrew