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