It seems to me this problem related to PSTricks so I have to modify the previous question.
\psset{fillstyle=solid,linecolor=red} that I define globally outside the preview environment can affect the graphics object. But why do I have to put \psset{fillcolor=green} inside the preview environment to make it works?
\documentclass[preview,border=12pt]{standalone}
\usepackage{pstricks}
\psset{fillstyle=solid,linecolor=red}
% the following setting will be ignored by preview
% \psset{fillcolor=green}
\begin{document}
\preview
% Thus the setting must be inside the preview, does it seem strange to you?
\psset{fillcolor=green}
\psframebox{Karl's students}
\endpreview
\end{document}
Is fillcolor very special in this case?


previewenvironment gets executed after\begin{document}. Otherwise usecropoption instead ofpreviewin the class options. – percusse Mar 15 at 15:05fillcoloroption. – Click Me Mar 15 at 15:07\preview. The issue comes up whether you usepreviewor not. It seems to have to do with where you call\psset. Setting things in the preamble doesn't always have the desired effect. Not sure why at this point. If you place your\psset{fillcolor=green}immediately afterbegin{document}it will work, but not if you place it inside the preamble. – A.Ellett Mar 15 at 18:00