%%
%% The LaTeX Companion, 3ed
%%
%% Example 9-6-9 on page I-714 in "Coloring fonts".
%%
%% 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.
%%

%Next line to access new features, see Chapter 2:
\DocumentMetadata {}

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{99.0pt}

%!TEX program = lualatex
%suppress colorspace code:
\RemoveFromHook{begindocument/before}[tlc3exa]
%l3color separation:
\ExplSyntaxOn
 \color_model_new:nnn { tlc3blue } { Separation }
    {
      name = PANTONE~3005~U ,
      alternative-model = cmyk ,
      alternative-values = {1, 0.56, 0,0},
    }
  \color_set:nnn{blue}{tlc3blue}{1}
\ExplSyntaxOff

%StartShownPreambleCommands
\usepackage{xcolor,fontspec}  \setmainfont{EB Garamond}
%StopShownPreambleCommands

\begin{document}
\Large\bfseries
\makebox[0pt][l]{\addfontfeature{Color=black,Opacity=0.5}%
                 Text in black.}%
\hspace{1pt}\addfontfeature{Color=blue,Opacity=0.7}Text in blue.\\
\textcolor{red}{Text still in blue and not red!}
\end{document}