I want to highlight text in a table using my own color definitions. The table is a `dcolumn` table. It doesn't work, I get the error messages `! Missing } inserted.` and `! Extra }, or forgotten $.` three times.

Below is a min example for the `beamer` class (I did not check out other classes).

```
\documentclass{beamer}

\usepackage[utf8]{inputenc}
\usepackage{default}
\usepackage{color, colortbl}
\usepackage{booktabs, dcolumn}
# Now I create my own color to highlight text
\definecolor{red4}{rgb}{0.545,0.000,0.000}
\newcommand{\mcdr}[1]{{{\bf \color{red4}#1}}}

\begin{document}
#-----------
\begin{frame}

\begin{table}
  \begin{tabular}{p{1cm} D{.}{.}{3.5}@{} }
    \toprule
    average & {\mcdr{-0.01}}     \\
  \end{tabular}
\end{table}

\end{frame}
#-----------
\end{document}

```

However, embedding `\mcdr` in a normal table, everything works fine:

```
  \begin{center}
   \begin{tabular}{l | l }
     early& {\mcdr{0.1}}  \tabularnewline
     late& \textit{0.11} \tabularnewline
   \end{tabular}
  \end{center}

```