\documentclass{beamer}
\usetheme{Boadilla}
\usecolortheme{seahorse}
\usefonttheme{serif}
\usepackage[T1]{fontenc}
\usepackage[french]{babel}
\usepackage{lipsum}
%\usepackage{graphicx,xcolor}
%\usepackage{amsmath,amssymb,amsfonts}
\title{Titre}
\subtitle{Sous-titre}
\author{Auteur}
\date{\today}
\setbeamercolor{author}{fg=green}
\setbeamercolor{date}{fg=red}
\begin{document}
\begin{frame}
\titlepage
\end{frame}
\end{document}\end{document}
![alt text][1]
[1]: https://texnique.fr/osqa/upfiles/document_dmCPDyT.png
