# How to color delimiters

I have some special delimiters that I want to add to a glossary, those get hyperlinks and colors etc. However when i want to use those delimiters, using \left, \right and \middle becomes impossible. I think with the following question fixed I can create my hyperlinked delimiters:

How to color delimiters:

As a minimal working example I have:

$\left\textcolor{red}{(}a\right)$


What i would like to have is (Created without \left \right):

This gets the error: ! Missing delimiter (. inserted).

Trying this :

$\textcolor{red}{\left(}a\right)$


results in ! Extra }, or forgotten \right.

Who can help me?

use it this way:

$\color{red}\left(\normalcolor a\right)$


or

$\textcolor{red}{\big(} a\big)$


There a \big, \bigg, \Big, and \Bigg

• this will not work if the current color is not the \normalcolor. And as I want to use this in a command, this will not work for me. And put this in a hyperlink will not work with this solution. – J. van Hoorn Jul 11 '12 at 12:02
• then you can only use \big et al (see edit). – user2478 Jul 11 '12 at 12:06
• However, i do not want the delimiters to be big :) They should fit, that is why I want to use \left and \right – J. van Hoorn Jul 11 '12 at 15:49

Here is macro that can easily be extended to different styles of brackets:

# Notes:

## Code:

\documentclass{article}
\usepackage{xcolor}

\newcommand{\BracKern}{\kern-\nulldelimiterspace}
\makeatletter
\newcommand{\@Brac}[3]{% #1,#3 = left/right bracket type
\mathopen{\color{red}\left#1\vphantom{#2}\BracKern\right.}% left bracket
#2%  content
\mathclose{\left.\BracKern\vphantom{#2}\right#3}% right bracket
}
\newcommand{\bracr}[1]{\@Brac{(}{#1}{)}}%
\newcommand{\bracs}[1]{\@Brac{[}{#1}{]}}%
\newcommand{\bracc}[1]{\@Brac{\{}{#1}{\}}}%
\makeatother

\begin{document}
$\bracr{a}$  $\displaystyle\bracr{\frac{1}{2}}$
$\bracs{a}$  $\displaystyle\bracs{\frac{1}{2}}$
$\bracc{a}$  $\displaystyle\bracc{\frac{1}{2}}$
\end{document}