更改 beamer 中正确选项的颜色

Question

在幻灯片放映期间，使用 ex_test 包中的命令 \True 来为问题的正确答案着色。但我需要使用两个框架来实现这一点，一个没有 \True，一个有 \True。我怎么才能只用一个框架来实现呢？抱歉我的英语不好。非常感谢。

\begin{frame}[plain]
        \begin{ex}
            In this box, do not color the true answer
            \choice
            {answer1}
            {answer2}
            {answer3}
            {answer4}
        \end{ex}
\end{frame}

\setcounter{ex}{0}
\begin{frame}[plain]
    \begin{ex}
        In this box, color the true answer
        \choice
        {\True answer1}
        {answer2}
        {answer3}
        {answer4}
    \end{ex}
\end{frame}

背面链接：https://www.overleaf.com/3696313321nqzcsxrjdcsh

Answer 1

您可以更改包中的命令ex_test以自动创建第二个覆盖：

\documentclass[aspectratio=169,t,hyperref={pdfpagemode=FullScreen}]{beamer}
\makeatletter
\let\th@plain\relax
\makeatother
\usepackage[color]{ex_test}
\renewtheorem{ex}{\color{blue!50!black} \small \fontfamily{qag}\selectfont Question}
\usepackage{mathptmx}
%\usepackage{hyperref}
%\hypersetup{pdfpagemode=FullScreen}        
\usefonttheme{professionalfonts}
\usepackage{framed}

\makeatletter
\def\colorEX{\only<2>{\color{red}}}
\renewcommand{\begindapan}{
\@ifnextchar\True
{
\begin{minipage}[t]{\widthalpha}
\alt<2>{\TrueEX}{\FalseEX}
\end{minipage}
\begin{minipage}[t]{\dorong}
}
{
\begin{minipage}[t]{\widthalpha}
\FalseEX
\end{minipage}
\begin{minipage}[t]{\dorong}
}
}
\makeatother

\begin{document}
\Opensolutionfile{ans}
\begin{frame}[plain]
    \setcounter{ex}{0}
        \begin{ex}
            In this box, do not color the true answer
            \choice
            {\True answer1}
            {answer2}
            {answer3}
            {answer4}
        \end{ex}
\end{frame}


\Closesolutionfile{ans}
\end{document}