[Tex/LaTex] Piecewise highlighting in beamer presentation

Question

I would like to do the following with beamer: All items of an itemize environment should be displayed in gray. The current item should be highlighted in black while all others remain grayed out, but visible (So for the example I would like to get three slides in the end: "Hallo" in black on slide 1, the rest in gray; "Welt" in black on the 2nd slide, all other items in gray, etc.). I just went through the manual, could not find any specific code to do so.

\documentclass{beamer}
\begin{document}
\frame{
  \begin{itemize}
    \item Hallo
    \item Welt
    \item Foobar
  \end{itemize}
}
\end{document}

Answer 1

\documentclass{beamer}
\begin{document}
\frame{%
\setbeamercolor{normal text}{fg=gray,bg=}
\setbeamercolor{alerted text}{fg=black,bg=}
\usebeamercolor{normal text}
\begin{itemize}
\item \alert<+>{Hallo}
\item \alert<+>{Welt}
\item \alert<+>{Foobar}
\end{itemize}
}
\end{document}