\DocumentMetadata{tagging = on, pdfstandard = ua-2}

\documentclass{ltx-talk}

\title{Setting opacity}

\EditInstance{hidden}{std}{opacity = 0.15}

\begin{document}

\begin{frame}
  \begin{itemize}[<+->]
    \item First
    \item Second
    \item Third
  \end{itemize}
\end{frame}

\end{document}
