%%
%% The LaTeX Companion, 3ed
%%
%% Example 11-7-24 on page II-208 in "Color in formulas".
%%
%% 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{tlc3examargin}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{135.0pt}

  % Shorten the vertical size of the example ...
  \AtBeginDocument{%
    \setlength\abovedisplayskip{.1\abovedisplayskip}%
    \setlength\belowdisplayskip{.1\belowdisplayskip}%
  }

%StartShownPreambleCommands
\usepackage{color}
%StopShownPreambleCommands

\begin{document}
\[ \mathcolor{blue}{\sum}_{i=1}^n x_i
   \mathcolor{blue}{ = \left\{} \frac{1}{2}
   \mathcolor{blue}{\right\}}^{\alpha+\beta}  \]
\end{document}