Welcome to TeX.SE! Something like this?
\documentclass{article}
\usepackage{colortbl}
\usepackage{tikz}
\usetikzlibrary{tikzmark}
\begin{document}
\begin{center}
\tikzmarknode{tab}{\begin{tabular}{|c!{\color{red}\vline}c|c|c|c|}\hline
$ \star $ & 1 & 2 & 3 & 4\\
\arrayrulecolor{red}\hline\arrayrulecolor{black}
1 & 4 & 3 & 2 & 1\\ \hline
2 & 3 & 1 & 4 & 2\\ \hline
3 & 2 & 4 & 1 & 3\\ \hline
4 & 1 & 2 & 3 & 4\\ \hline
\end{tabular}}
\begin{tikzpicture}[overlay,remember picture]
\draw[thick,green!60!black,shorten <=6mm] (tab.north west) -- (tab.south east);
\end{tikzpicture}
\end{center}
\end{document}
Or with selected lines thicker but slightly more complicated code.
\documentclass{article}
\usepackage{colortbl}
\usepackage{tikz}
\usetikzlibrary{tikzmark}
\newlength{\savedwidth}
\begin{document}
\begin{center}
\tikzmarknode{tab}{\global\savedwidth\arrayrulewidth % p. 6 of colortbl docu
\arrayrulewidth0.2pt
\begin{tabular}{|c!{\arrayrulewidth0.8pt\color{red}\vline}c|c|c|c|}\hline
$ \star $ & 1 & 2 & 3 & 4\\
\noalign{\global\setlength\arrayrulewidth{0.8pt}}%
\arrayrulecolor{red}\hline\arrayrulecolor{black}\noalign{\global\arrayrulewidth0.2pt}
1 & 4 & 3 & 2 & 1\\ \hline
2 & 3 & 1 & 4 & 2\\ \hline
3 & 2 & 4 & 1 & 3\\ \hline
4 & 1 & 2 & 3 & 4\\ \hline
\end{tabular}}\global\arrayrulewidth\savedwidth
\begin{tikzpicture}[overlay,remember picture]
\draw[line width=0.8pt,green!60!black,shorten <=6mm,shorten >=1pt] (tab.north west) -- (tab.south east);
\end{tikzpicture}
\end{center}
\end{document}