[pstricks] Colors of overlapping objects

[Arne Hallam]

Is there a way to control the color of the overlap as compared to having 
it done automatically as in the following.  I am using this in Powerdot 
and don't really like the brown given the backdrop of my slides.


\documentclass[12pt]{article}
\usepackage[dvipsnames,svgnames]{xcolor}
\usepackage{pst-eucl}

\begin{document}
  \begin{pspicture}(0,0)(15,10)
     \pnodes(2.5,4){A}(9.5,4){B}(6,8.5){C}
     \pnodes(4.3,7){D}(7.3,7){E}(5.5,3.5){F}(4.3,5.5){G}
     \def\RI{6}\def\RII{4}%
\psellipse[linecolor=green,fillstyle=solid,fillcolor=green!60,opacity=0.4](A)(\RI,\RII)
\psellipse[linecolor=red,fillstyle=solid,fillcolor=red!60,opacity=0.4](B)(\RI,\RII)
\psellipse[linecolor=blue,fillstyle=solid,fillcolor=SkyBlue!80,opacity=0.4](C)(\RI,\RII)
     \uput{0pt}[180](A){\Huge \bfseries Environment}
     \uput{10pt}[0](B){\Huge \bfseries Economic}
     \uput{25pt}[90](C){\Huge \bfseries Social}
     \uput{0pt}[180](D){\LARGE \bfseries Bearable}
      \uput{0pt}[0](E){\LARGE \bfseries  Equitable}
      \uput{0pt}[270](F){\LARGE  \bfseries Viable}
     \uput{0pt}[0](G){\Large \bfseries Sustainable}
   \end{pspicture}
   \end{document}