hyperref package: how to color citations only

I would like to use the hyperref package to color citations only, but it seems that it colors every link.

For example here:

\documentclass{article}
    
\usepackage{hyperref}
\hypersetup{
    citecolor  = blue,
        colorlinks = true,
    }
    
\begin{document}
        
\tableofcontents
\section{This title should be in red in the TOC}
        
This citation \cite{a} is blue.
        
\begin{thebibliography}{99}
   \bibitem{a} Andros, Using hyperref for a citation, StackExchange, 2022.
\end{thebibliography}
        
\end{document}

I would like the citation to be blue, but I don't want the items in the table of contents to be red.

Thanks

Solution

I would not activate colorlinks with beamer. This can break the carefully constructed colour themes in sometimes very surprising places.

Instead you could change the text colour for the citation:

\documentclass{beamer}

\usetheme{metropolis}

\usepackage{xpatch}
\usepackage{xspace}

\makeatletter
\xpretocmd{\@citex}{\color{blue}}{}{}
\xapptocmd{\@citex}{\color{normal text.fg}\xspace}{}{}
\makeatother
\begin{document}
        
\begin{frame}
        
This citation \cite{a} is blue.
        
\begin{thebibliography}{99}
   \bibitem{a} Andros, Using hyperref for a citation, StackExchange, 2022.
\end{thebibliography}
        
\end{frame}        
\end{document}