Using beamer colors

Question

To avoid having too many colors, I use beamer's colors to emphasize items of my text. It looks something like this:

\documentclass[xcolor=dvipsnames]{beamer} 
\usetheme{Madrid}

\newcommand{\gn}[1]{\textcolor{block title example.bg}{{}#1{}}}

\begin{document}

  \begin{frame}{Green text}
  \gn{This isn't working.}

  \begin{example}[boring example]

    nothing to see here.
    \end{example}

  \gn{This is green.}

  This is black.
  \end{frame}
  \end{document}

Now, if I try to use the color before beamer uses it for the first time (as in "This isn't working"), I get the error:

Package xcolor Error: Undefined color `block title example.bg'.

Is there a way to resolve this?

Answer 1

\usebeamercolor[bg]{block title example} will use the color

\documentclass[xcolor=dvipsnames]{beamer} 
\usetheme{Madrid}

\newcommand{\gn}[1]{{\usebeamercolor[bg]{block title example}#1}}

\begin{document}

  \begin{frame}{Green text}
  \gn{This isn't working.}

  \begin{example}[boring example]

    nothing to see here.
    \end{example}

  \gn{This is green.}

  This is black.
  \end{frame}
  \end{document}