Change color of itemize in beamer alertblock

Question

How can I change the color of bullets in an itemize list within an alertblock in beamer?

I use

  \setbeamercolor{itemize item}{<color>}

to set the color of the bullets throughout the document. But I want a different color when the bullets are inside an alertblock environment. I've tried

\setbeamercolor{block itemize item alerted}{<color>}

and

\setbeamercolor{block alerted itemize item}{<color>}

but neither seems to do anything.

Update: This is not the same question as Custom beamer blocks for pros and cons?. I want to modify the alertblock environment. I don't want to create a new environment.

Answer 1

Just alter the parent structure:

\documentclass{beamer}
%title
\setbeamercolor{block title alerted}{fg=white,bg=brown}
%body
\setbeamercolor{block body alerted}{fg=black!90,bg=brown!60!yellow}
% parent of all alerts default is red
\setbeamercolor{alerted text}{fg=green}

\begin{document}
\frame{
\begin{itemize}
\item item 
\end{itemize}
\begin{alertblock}{alert block}
\begin{itemize}
\item item 
\end{itemize}
\end{alertblock}
}
\end{document}

I would not recommend to use exactly this color scheme but it shows how itemize items and the background can be adjusted individually. This will effect enumerate environments and any other alert as well.

Additional tipp: instead of guessing beamer templates which are not listed in the guide just look them up in the beamer<color/inner/outer>themedefault.sty files in the beamer tree.

Answer 2

If you want to modify only the alerted block environment and/or you used something like \setbeamercolor*{itemize}{fg=\colortheme, bg=white} to use a custom color on most items you'll want to add a template only for alert blocks, like this:

\addtobeamertemplate{block alerted begin}{%
  \setbeamercolor*{item}{fg=red}%
}{}

This will only change the color of itemize items inside alerted blocks.