How to write \clines (or \hhline) in colored tables so that the color of the cell does not hide the line?
Here are two solutions but neither of them works fine.
\documentclass[a4paper,11pt]{article}
\usepackage{colortbl}
\usepackage{hhline}
\usepackage{multirow}
\begin{document}
First try with \verb+\cline+
\begin{figure}[hbt]
\centering
\small\sf
\begin{tabular}{|c|c|>{\columncolor[gray]{.8}}c|c|c|c|} \hline
\rowcolor[gray]{.8} & & & \multicolumn{3}{c|}{Year} \\ \hline
\rowcolor[gray]{.8} Country & GOR & UA & 2006 & 2007 & 2008 \\ \hline
\cellcolor[gray]{.8} & \cellcolor[gray]{.8} & Milton Keynes & 92 & 94 & 96 \\\cline{3-6}
\cellcolor[gray]{.8} & \multirow{-2}{*}{\cellcolor[gray]{.8}South East} & Reading & 58 & 58 & 60 \\\cline{2-6}
\multirow{-3}{*}{\cellcolor[gray]{.8}England} & \cellcolor[gray]{.8} South West & Bournemouth& 71 & 72 & 73 \\ \hline
\cellcolor[gray]{.8} & \cellcolor[gray]{.8} & Cardiff & 132.1 & 134.2 & 136.7 \\\cline{3-6}
\multirow{-2}{*}{\cellcolor[gray]{.8}Wales} & \multirow{-2}{*}{\cellcolor[gray]{.8}Wales} & Newport & 58.7 & $\perp$ & 59.6 \\ \hline
\end{tabular}
\caption{The clines are somehow hidden by the cell color}
\end{figure}
Second try with \verb+\hhline+
\begin{figure}[hbt]
\centering
\small\sf
\begin{tabular}{|c|c|>{\columncolor[gray]{.8}}c|c|c|c|} \hline
\rowcolor[gray]{.8} & & & \multicolumn{3}{c|}{Year} \\ \hline
\rowcolor[gray]{.8} Country & GOR & UA & 2006 & 2007 & 2008 \\ \hline
\cellcolor[gray]{.8} & \cellcolor[gray]{.8} & Milton Keynes & 92 & 94 & 96 \\\hhline{~~----}
\cellcolor[gray]{.8} & \multirow{-2}{*}{\cellcolor[gray]{.8}South East} & Reading & 58 & 58 & 60 \\\hhline{~-----}
\multirow{-3}{*}{\cellcolor[gray]{.8}England} & \cellcolor[gray]{.8} South West & Bournemouth& 71 & 72 & 73 \\ \hline
\cellcolor[gray]{.8} & \cellcolor[gray]{.8} & Cardiff & 132.1 & 134.2 & 136.7 \\ \hhline{~~----}
\multirow{-2}{*}{\cellcolor[gray]{.8}Wales} & \multirow{-2}{*}{\cellcolor[gray]{.8}Wales} & Newport & 58.7 & $\perp$ & 59.6 \\ \hline
\end{tabular}
\caption{Now there is a white line where it shouldn't be}
\end{figure}
\end{document}




colortblpackage documentation (see section Less fun with\cline). – khyox Oct 16 '18 at 21:00