[pstricks] \psmatrix: different colsep values

[Joshua Reyes]

Hi List,

I'm trying to make a small diagram using a psmatrix:

\documentclass{amsart}
\usepackage[usenames]{pstcol}
\usepackage{pstricks, pst-node, pst-tree}
\begin{document}
$
\psmatrix[colsep=0.45cm, rowsep=0.1cm, mnode=circle]
[fillstyle=solid, fillcolor=BurntOrange]  & [fillstyle=solid,
fillcolor=CornflowerBlue] & & [fillstyle=solid, fillcolor=BurntOrange]
& [fillstyle=solid, fillcolor=BurntOrange]
\psset{nodesep=0.05cm}
\ncline{->}{1,2}{1,4}
\psset{linestyle=none}
\ncline{-}{1,1}{1,2}
\lput*{:U}{\textsf{\textbf{+}}}
\endpsmatrix
$
\end{document}

I'd like to decrease the space between the two right-most orange
nodes, but I'm having trouble do so. I tried to use this post as a
model:
http://tug.org/mailman/htdig/pstricks/2006/003547.html,
but \makebox changed the style of the nodes and I wasn't sure how to
get it back to the psmatrix default.

Any pointers would be much appreciated.
best,
Josh