We have many issues when using xcolor
with right to left text (pdflatex and xelatex)
Colors bizarre results with right to left text
The answer suggest to use the command from fontspec
package
{\addfontfeature{Color=red} colored text here }
I thought if it is possible to change the definition of command \color
to be the same as Color
from fontpec we can solve those issues even partially
\documentclass{beamer}
\usepackage{fontspec}
\setmainfont[Script=Arabic]{Amiri}
\usefonttheme{serif}
% redefine \color{#1} to be the same as \addfontfeature{Color=#1}
\usepackage[rldocument]{bidi}
\begin{document}
\raggedleft
\begin{frame}{title}
\begin{enumerate}\raggedleft
\item
text from right to left \alert{text from right to left text from right to left
text from right to left} out
\end{enumerate}
\end{frame}
\renewcommand{\alert}[1]{{\addfontfeature{Color=red}#1}}
\begin{frame}{title}
\begin{enumerate}\raggedleft
\item
text from right to left \alert{text from right to left text from right to left
text from right to left} out
\end{enumerate}
\end{frame}
\end{document}