[pstricks] pstricks and beamer transparency

[Ales Horak]

Hello,

I am using beamer with pstricks intensively in preparation of
lecture slides about artificial intelligence. when I want to use
beamer transparency effects the pstricks graphics does not change
color to grey as the text does (I am attaching an example).

is there a way to adapt (or use) pstricks to this behavior?
the pstricks graphics may even be hidden completely before its
turn - the grey color is not necessarry.

best regards,
-- 
Ales Horak
Faculty of Informatics
Masaryk University Brno
Czech Republic