Conflicting between `\everydisplay` and `eqnarray` environment in `beamer` class

Question

In my presentation, I want every math to be blue and every display math to be red. In my attempt, I have tried to compile the following MWE

\documentclass{beamer}
\everymath{\color{blue}}
\everydisplay{\color{red}}
\begin{document}
\begin{frame}
\begin{eqnarray}
a &=& b\\
c &=& d
\end{eqnarray}
\begin{equation}
E=mc^2
\end{equation}
\end{frame}
\end{document}

I got an error say Improper \halign inside $$'s. \end{frame}. If I disable \everydisplay command, there is no error. However, this is not my desire! I do want every display math to be typesetted in red. How can we achieve this?

Just avoid eqnarray in every circumstances. – egreg Aug 02 '17 at 08:58 — egreg, Aug 02 '17 at 08:58
@egreg Could you tell us the reasons why? – Say OL Aug 02 '17 at 16:38 — Say OL, Aug 02 '17 at 16:38

score 6 · Accepted Answer · answered Aug 02 '17 at 09:06

6

Use beamer's own commands to change colours.

\documentclass{beamer}
\setbeamercolor{math text inlined}{fg=blue}
\setbeamercolor{math text displayed}{fg=red}

\begin{document}
\begin{frame}
\begin{align}
a &= b\\
c &= d
\end{align}
\begin{equation}
E=mc^2
\end{equation}
$a=b$
\end{frame}
\end{document}

Note that you will get some unfortunate effects with equation labels if you use different colours for inline and displayed mathematics.

answered Aug 02 '17 at 09:06

Ian Thompson

43,767

Great! I could actually read Beamer manual before posting this question :) – Say OL Aug 02 '17 at 09:36
It's a long read... – Ian Thompson Aug 02 '17 at 09:46
You are right. Sometimes it is less efficient than surfing the internet or asking in the forum! – Say OL Aug 02 '17 at 16:42

Conflicting between `\everydisplay` and `eqnarray` environment in `beamer` class

1 Answers1