So, I have a very simple table I'm trying to get working. The idea is to have the first, second, and last column/row separators be thick and colored a shade of green, while the first column and first row are given a background of pale yellow. At the same time I still need normal column/row separators.
However, my initial attempts to achieve this result have been met with what I believe to be multiple small issues. To list them, the most major issue is that the first and second column separators extend below the bottom of the table. Second, the normal \hline is drawing over the vertical rules, when I would prefer the latter. Third, changing the cell color draws over parts of the separators, making them appear thinner in certain places. Fourth, the normal vertical rules don't display consistently when bordered by colored cells.
Here is my minimal working example. I used the xcolor package to help define the colors and colortbl to add colors to the \hrule in the newcommands and color to the \newcolumntypes.
\documentclass[10pt]{article}
\usepackage{xcolor}
\usepackage{colortbl}
\definecolor{forestgreen}{RGB}{ 39, 159, 39}
\definecolor{paleyellow}{RGB}{ 255, 255, 212}
\newcommand{\ywl}{\cellcolor{paleyellow}}
\newcommand{\grline}{\noalign{\color{forestgreen}\hrule height 1.6pt}}
\newcolumntype{(}{@{\color{forestgreen}\vrule width 1.6pt\hskip\tabcolsep}}
\newcolumntype{"}{@{\hskip\tabcolsep\color{forestgreen}\vrule width 1.6pt\hskip\tabcolsep}}
\newcolumntype{)}{@{\hskip\tabcolsep\color{forestgreen}\vrule width 1.6pt}}
\begin{document}
\begin{tabular}{(c"c|c|c|c)}
\grline
\ywl &\ywl 0 &\ywl a &\ywl b &\ywl c \\
\grline
\ywl 0 & 0 & 0 & 0 & 0 \\
\hline
\ywl a & 0 & a & b & c \\
\hline
\ywl b & 0 & 0 & 0 & 0 \\
\hline
\ywl c & 0 & a & b & c \\
\grline
\end{tabular}
\end{document}
\documentclass
command, include any necessary packages and be as small as possible to demonstrate your problem. At the moment we have to guess what packages etc you are using before we can compile your code.