On Sat, Nov 1, 2008 at 2:06 AM, Renaud Aubin <aubin@nibua-r.org> wrote:

> Thank Luigi for your response,  the problem is that the background color
> rendering isn't the same if you comment out or not the following line :
> draw fullcircle scaled 10cm shifted (0cm,0.25*\overlayheight) withcolor
> transparent(1,0.5,white) withpen pencircle scaled 2cm;
>
true

>
> After some experiments, the problem is solved ( hence not understood
> ???) using rgb=no in setupcolors...
>
They seem differents again

>
> It's maybe a viewer-centric problem : I use acroread 8.1.2 under linux.
>
no, I don't believe.
Try to investigate with \pdfcompresslevel0 at the beginning

-- 
luigi