Se vuoi solo cambiare il colore dei box di tipo esempio, è sufficiente mettere nel preambolo
`\setbeamercolor{block title example}{fg=Purple,bg=purple!20}
\setbeamercolor{block body example}{fg=orange,bg=orange!10}
`
Se invece vuoi crearti dei box colorati indipendentemente dai classici theorem, alertbox e examplebox ecco una carrellata di esempi (serve il pacchetto lipsum)
`
\newcommand{\ciao}[1]{\begin{#1} \lipsum[1]\end{#1}} % tests blocks colors
\begin{frame}[allowframebreaks]{Test blocks predefinis}
\ciao{Theorem}
\ciao{theorem}
\ciao{Proof}
\ciao{proof}
\ciao{Corollary}
\ciao{corollary}
\ciao{fact}
\ciao{Lemma}
\ciao{lemma}
\ciao{Problem}
\ciao{problem}
\ciao{solution}
\ciao{definitions}
\ciao{Definition}
\ciao{definition}
\ciao{Examples}
\ciao{examples}
\ciao{Example}
\ciao{example}
\end{frame}
\renewcommand{\ciao}[2]{\begin{#1}{#2} \lipsum[1]\end{#1}} % tests blocks colors
\begin{frame}[allowframebreaks]{Test blocks avec titre personalisé ou sans titre}
\ciao{block}{Avec titre}
\ciao{block}{}
\ciao{exampleblock}{Avec titre}
\ciao{exampleblock}{}
\ciao{alertblock}{Avec titre}
\ciao{alertblock}{}
\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{frame}{Test blocks personalisés}
\setbeamercolor{uppercol}{fg=white,bg=Orange!50}%
\setbeamercolor{lowercol}{fg=black,bg=orange!10}%
\begin{beamerboxesrounded}[upper=uppercol,lower=lowercol,shadow=true]{Pippo}
$A = B$.
\end{beamerboxesrounded}
\begin{beamerboxesrounded}[upper=block title,lower=block body,shadow=true]{Topolino}
Bla bla $A^\mathrm{aaa} = B^\text{aaa}$ bla bla.
\end{beamerboxesrounded}
\begin{beamerboxesrounded}[upper=block title alerted,lower=block body alerted,shadow=true]{Paperino}
Bla bla $A^\mathrm{aaa} = B^\text{aaa}$ bla bla.
\end{beamerboxesrounded}
\begin{beamerboxesrounded}[upper=block title example,lower=block body example,shadow=true]{Qui Quo Qua}
Bla bla \[A^\mathrm{aaa} = B^\text{aaa}\] bla bla.
\end{beamerboxesrounded}
\begin{beamercolorbox}[ht=2.5ex,dp=1ex,center]{title in head/foot}
\usebeamerfont{title in head/foot}
Minnie
\end{beamercolorbox}%
\hbox{%
\begin{beamercolorbox}[ht=2.5ex,wd=0.5\textwidth,dp=1ex,center]{author in head/foot}
\usebeamerfont{author in head/foot}
Nonna papera
\end{beamercolorbox}%
\begin{beamercolorbox}[ht=2.5ex,wd=0.5\textwidth,dp=1ex,center]{date in head/foot}
\usebeamerfont{date in head/foot}
Clarabella
\end{beamercolorbox}
}
\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{frame}{Box colorés}
\colorlet{contour}{author in head/foot.bg}
\colorlet{fond}{date in head/foot.bg}
Bla bla bla bla bla bla bla bla bla bla bla bla bla \fcolorbox{contour}{fond}{bla bla bla bla bla bla} bla bla bla bla bla bla bla bla bla bla bla
\end{frame}`