\input regression-test.tex
\documentclass{article}
\usepackage{osglistings}
\DeclareOsgListingsPalette{my-theme}{
  keyword = {model=HTML, value=8A2BE2},
  string  = {alias=keyword},
}
\makeatletter
\newcommand\CheckLatexMinted{%
  \ifx\minted@executable@version\relax
    \TYPE{latexminted-unavailable}%
  \else
    \TYPE{latexminted-ok}%
  \fi}
\makeatother
\begin{document}
\START

\OMIT
\begin{osglisting}[style=plain]{python}
def foo(): pass
\end{osglisting}
\TIMO
\CheckLatexMinted
\TYPE{default-palette-ok}

\OMIT
\begin{osglisting}[style=plain, palette=my-theme]{python}
def foo(): pass
\end{osglisting}
\TIMO
\TYPE{custom-palette-ok}

\UseOsgListingsPalette{my-theme}
\OMIT
\begin{osglisting}[style=plain]{python}
def foo(): pass
\end{osglisting}
\TIMO
\TYPE{global-palette-switch-ok}

\UseOsgListingsPalette{osglistings-default}

\END
\end{document}