# Color empty columns in tables

I would like to color these empty columns, but I couldn't find a way to do it. I tried already defining my own column type, however, inserting it destroys the normal look of empty columns.

Here my minimal working example:

\documentclass{article}
\usepackage[table]{xcolor}

\begin{document}
\begin{center}
\begin{tabular}{||l c||}
\hline
\rowcolor{black!10}
Column 1 & Column 2 \\ [0.7ex]
\hline\hline
\rowcolor{green!20}
Entry 1 & Entry 2 \\
\hline
\rowcolor{green!25}
Entry 3 & Entry 4 \\
\hline
\end{tabular}
\end{center}
\end{document}


I would like to color the outer columns black.
Thank you!

Solution: For black coloring, thick border lines are enough. For other colors, see my colortbl solution.

• Take a look at the hhline package, if I remember correctly, it does support coloured double lines. – Skillmon Mar 7 '18 at 22:52
• Which outer columns? Maybe you mean the space between the rules of double rules? – Bernard Mar 7 '18 at 22:52
• @Bernard exactly, I mean the space between the outer double rules. – mightymicha Mar 7 '18 at 22:54
• @Skillmon Thank you, I will look into that. – mightymicha Mar 7 '18 at 22:54
• If it's to be black, this simply means a very thick vertical rule. – Bernard Mar 7 '18 at 22:57

\documentclass{article}
\usepackage[table]{xcolor}

\begin{document}
\begin{center}
\begin{tabular}{!{\vrule width 5pt}l c!{\vrule width 5pt}}
\hline
\rowcolor{black!10}
Column 1 & Column 2 \\ [0.7ex]
\hline\hline
\rowcolor{green!20}
Entry 1 & Entry 2 \\
\hline
\rowcolor{green!25}
Entry 3 & Entry 4 \\
\hline
\end{tabular}
\end{center}
\end{document}


Here is a solution, if I've well understood what you want:

\documentclass{article}
\usepackage[table]{xcolor}

\begin{document}

\begin{center}
\setlength{\extrarowheight}{2pt}
\begin{tabular}{!{\vrule width \dimexpr\doublerulesep+2\arrayrulewidth\relax}l c!{\vrule width \dimexpr\doublerulesep+2arrayrulewidth\relax}}
\hline
\rowcolor{black!10}
Column 1 & Column 2 \\ [0.7ex]
\hline\hline
\rowcolor{green!20}
Entry 1 & Entry 2 \\
\hline
\rowcolor{green!25}
Entry 3 & Entry 4 \\
\hline
\end{tabular}
\end{center}

\end{document}


A variant:

\begin{center}
\setlength{\extrarowheight}{2pt}\begin{tabular}{{@{\vrule width \dimexpr\doublerulesep+2\arrayrulewidth\relax}c@{\vrule width \dimexpr\doublerulesep+2\arrayrulewidth\relax}}}
\begin{tabular}{!{}l c!{}}
\hline
\rowcolor{black!10}
Column 1 & Column 2 \\ [0.7ex]
\hline\hline
\rowcolor{green!20}
Entry 1 & Entry 2 \\
\hline
\rowcolor{green!25}
Entry 3 & Entry 4 \\
\hline
\end{tabular}
\end{tabular}
\end{center}


Ok after @Skillmon's tip I looked into that package and found a reference to the colortbl package, which solved it:

        \doublerulesepcolor{black}
\begin{tabular}{||l c||}
\doublerulesepcolor{white}
\hline
\rowcolor{black!10}
Column 1 & Column 2 \\ [0.7ex]
\hline\hline
\rowcolor{green!20}
Entry 1 & Entry 2 \\
\hline
\rowcolor{green!25}
Entry 3 & Entry 4 \\
\hline
\end{tabular}


You can have quite some fun with this:

    \setlength\arrayrulewidth{2pt}\arrayrulecolor{blue}
\setlength\doublerulesep{2pt}\doublerulesepcolor{yellow}
\begin{tabular}{||l c||}
\hline
\rowcolor{black!10}
Column 1 & Column 2 \\ [0.7ex]
\hline\hline
\rowcolor{green!20}
Entry 1 & Entry 2 \\
\hline
\rowcolor{green!25}
Entry 3 & Entry 4 \\
\hline
\end{tabular}


• note you had already loaded colortbl (that's the main effect of the [table] option to xcolor) – David Carlisle Mar 7 '18 at 23:37