%%
%% The LaTeX Companion, 3ed
%%
%% Example 1-3-5 on page I-17 in "Typographic conventions".
%%
%% 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{63.0pt}

  \setlength\parindent{10pt}
  \sloppy

%StartShownPreambleCommands
\usepackage{xcolor}
\definecolor{blue}{cmyk}{1,0.56,0,0}  % what we call `blue' in this book
\definecolor{red}{gray}{.7}     \definecolor{green}{gray}{.8}
\definecolor{yellow}{gray}{.9}
%StopShownPreambleCommands

\begin{document}
Black \textcolor{blue}{blue} \textcolor{red}{red} {\color{green} green}
\textcolor{yellow}{yellow} \colorbox{black!30}{\color{blue} blue}
\fcolorbox{blue}{blue!8}{\color{blue}bluish}
\end{document}