[Tex/LaTex] Change color of an item in beamer when moving to next time

Question

I have three items in a beamer slide. They appear one after the other when I press next.
My problem is I want the first two items to change color when the third item appears. Please explain how to do this.

Answer 1

No need to write everything twice, you can simply use \only<>{} to change the colour

\documentclass{beamer}

\begin{document}

\begin{frame}
        \begin{itemize}[<+->]
            \item \only<3>{\color{red}}1
            \item \only<3>{\color{red}}2
            \item 3
        \end{itemize}
\end{frame}

\end{document}  

---

To address the command about dvipsnames

Since beamer internally already loads the xcolor package you can pass the dvipsnames like this:

\documentclass[xcolor=dvipsnames]{beamer}

\begin{document}

\begin{frame}
        \begin{itemize}[<+->]
            \item \only<3>{\color{Peach}}1
            \item \only<3>{\color{Peach}}2
            \item 3
        \end{itemize}
\end{frame}

\end{document}