%%
%% The LaTeX Companion, 3ed
%%
%% Example A-4-1 on page II-672 in "Working with existing hooks".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{111.0pt}

%StartShownPreambleCommands
\usepackage{color}
\AddToHook{cmd/quote/after}{\color{blue}}
\AddToHook{cmd/quote/after}[quotesize]{\footnotesize}

%StopShownPreambleCommands

\begin{document}
All quotes are in blue:  \begin{quote} The Quote. \end{quote}
and in a smaller typeface:
                     \begin{quote} Another Quote. \end{quote}
\RemoveFromHook{cmd/quote/after}
but this one is black: \begin{quote} Final Quote! \end{quote}
\end{document}