\documentclass{article}
\usepackage{xcolor}
\usepackage{listings}
\makeatletter%
\lstdefinestyle{customLatex}{
language = [LaTeX]{TeX},
texcsstyle = *\bfseries\color{blue},
% Paramètre
keywordstyle = [1]\bfseries\color{orange},
% Valeur
keywordstyle = [2],%
%
texcs={
geometry,
},
keywords = [1]{
paper,
a4paper,
a5paper
},
alsoletter=0123456789,
}
\makeatother
\begin{document}
\begin{lstlisting}[style=customLatex]
\geometry{
a5paper,
paper = a5paper,
}
\end{lstlisting}
\end{document}\end{document}
![alt text][1]
[1]: https://texnique.fr/osqa/upfiles/Screenshot_2025-12-20_at_14.58.30.png
