[pstricks] color in graphic inclusions

[Michael Sharpe]

This might not be a real PSTricks issue, but it seems to be at the  
heart of the problem. I have two small black pdf images. image1.pdf is  
an image with just text, generated using dvips -E and eps2pdf.  
image2.pdf was generated the same way, but has both text and a  
PSTricks element. Both have no explicit color settings---just the  
default black. When I include the first image inside a red box using

%using pdflatex here with graphicx and xcolor
{\color{red}
\fboxsep=0pt
\fbox{%
\includegraphics{image1}%
}}

I get what I expected--a red frame around black text. However, the  
same TeX fragment with image2 gives me a red frame, and the image  
(both text and PSTricks parts) have changed color to red. If I insert  
\color{black} before \includegraphics, I get a black image again.

If I include the .eps files rather than the .pdf files, using latex  
rather than pdflatex, there is no such issue. (Using TeXLive 2007 and  
latest pstricks.)

Michael