\hhline adds white line where no line is intended

Question

In a table, containing colored cells, i want to have a \hline dividing only some cells, similar to \cline but compatible with coloring single cells with \cellcolor, which is possible by using \hhline with fitting parameters.

Now I have come to the appended code, which results in:

There are two points I want to work around.

First, the black cells should not be crossed by a white line. Since they will not be black in the final document, I need them to be not black, either. Is there a way to not draw any line at all? These cells should look like a multirow cell, colored consistently.

The second problem are the hline fragments at the right end of the table. How can I get rid of them?

Complete code:

\documentclass[11pt]{article}

\usepackage{color}
\usepackage{colortbl}
\usepackage{multirow}
\usepackage{hhline}

\setlength{\arrayrulewidth}{1pt}


\begin{document}
% Empty table
\begin{tabular}{*{5}{!{\vrule width 1.5pt}p{1.5cm}}!{\vrule width 1.5pt}l}
\centering 4 &
\centering 10 &
\centering 24 &
\centering 48 &
\centering 72 &\\ \hhline{*{5}{|-}|~|}
 &  &  &  &  & Optic tectum \\ \hhline{*{2}{|~}*{3}{|-}|~|}
 &  &  &  &  & Retina \\ \hhline{*{2}{|~}*{3}{|-}|~|}
 &  &  &  &  & Myomeres \\ \hhline{*{5}{|-}|~|}
 &  &  &  &  & Arches \\ \hhline{*{5}{|-}|~|}
\end{tabular} \\

\hspace*{1cm}

% Partically filled table
\begin{tabular}{*{5}{!{\vrule width 1.5pt}p{1.5cm}}!{\vrule width 1.5pt}l}
\centering 4 &
\centering 10 &
\centering 24 &
\centering 48 &
\centering 72 &\\ \hhline{*{5}{|-}|~|}
 & \cellcolor{black} &  & \cellcolor{green} &  & Optic tectum \\ \hhline{*{2}{|~}*{3}{|-}|~|}
 & \cellcolor{black} &  & \cellcolor{red} &  & Retina \\ \hhline{*{2}{|~}*{3}{|-}|~|}
 & \cellcolor{black} &  & \cellcolor{blue} &  & Myomeres \\ \hhline{*{5}{|-}|~|}
 & \cellcolor{blue} &  & \cellcolor{yellow} &  & Arches \\ \hhline{*{5}{|-}|~|}
\end{tabular}

\end{document}

Answer 1

You are specifying a final hhline fragment

\hhline{*{2}{|~}*{3}{|-}|~|}

You need

 \hhline{*{2}{|~}*{3}{|-}|~}

The "white line" is not a rule drawn over the black background it is just a lack of background, thus you need to fill it, the easiest way, as shown in the previous question is not to use ~ in the \hhline (which does exactly what you ask and does not draw any line at all) but instead use - but colour the rule using >{...} to match the cell colour.

Answer 2

1. If the look of black cells should be \multirow-esque, then colouring the lines black would do it. For this, I used a - instead of ~ to draw the horizontal rules for the second column;
2. Using | indicates a "vline which 'cuts' through a double (or single) hline" (according to the hhline documentation). Removing this from your \hhline specification at the end drops the "hline fragments."

3. Since you're using \vline 1.5pt as your column divisions, you might as well use

   \setlength{\arrayrulewidth}{1.5pt}
   

   to have a consistent look for your table. Otherwise you will notice little indents in your vertical rules.

Here's a MWE showcasing the above:

\documentclass[11pt]{article}
%\usepackage{color}% http://ctan.org/pkg/color
%\usepackage{multirow}% http://ctan.org/pkg/multirow
\usepackage{colortbl}% http://ctan.org/pkg/colortbl
\usepackage{hhline}% http://ctan.org/pkg/hhline

\begin{document}
% Empty table
\setlength{\arrayrulewidth}{1pt}%
\begin{tabular}{*{5}{!{\vrule width 1.5pt}p{1.5cm}}!{\vrule width 1.5pt}l}
\centering 4 &
\centering 10 &
\centering 24 &
\centering 48 &
\centering 72 &\\ \hhline{*{5}{|-}|~|}
 &  &  &  &  & Optic tectum \\ \hhline{*{2}{|~}*{3}{|-}|~|}
 &  &  &  &  & Retina \\ \hhline{*{2}{|~}*{3}{|-}|~|}
 &  &  &  &  & Myomeres \\ \hhline{*{5}{|-}|~|}
 &  &  &  &  & Arches \\ \hhline{*{5}{|-}|~|}
\end{tabular}

\bigskip

% Partically filled table
\setlength{\arrayrulewidth}{1.5pt}%
\begin{tabular}{*{5}{|p{1.5cm}}|l}
\centering 4 &
\centering 10 &
\centering 24 &
\centering 48 &
\centering 72 &\\ \hhline{*{5}{|-}|~}
 & \cellcolor{black} &  & \cellcolor{green} &  & Optic tectum \\ \hhline{|~*{4}{|-}|~}
 & \cellcolor{black} &  & \cellcolor{red} &  & Retina \\ \hhline{|~*{4}{|-}|~}
 & \cellcolor{black} &  & \cellcolor{blue} &  & Myomeres \\ \hhline{*{5}{|-}|~}
 & \cellcolor{blue} &  & \cellcolor{yellow} &  & Arches \\ \hhline{*{5}{|-}|~}
\end{tabular}

\end{document}

Answer 3

You can easily construct that table with {NiceTabular} of nicematrix. The rules specified the command \Hline (of nicematrix) are not drawn in the blocks (constructed by the command \Block).

\documentclass[11pt]{article}
\usepackage{nicematrix}
\setlength{\arrayrulewidth}{1pt}

\begin{document}

\begin{NiceTabular}{*{5}{p{1.5cm}}}[colortbl-like,last-col,vlines,rules/width=1.5pt]
\centering 4 &
\centering 10 &
\centering 24 &
\centering 48 &
\centering 72 &\\ 
\Hline
\Block{*-1}{} 
 & \Block[fill=red!15]{3-1}{} 
    &  & \cellcolor{green} &  & Optic tectum \\ 
\Hline
 &  &  & \cellcolor{red} &  & Retina \\ 
\Hline
 &  &  & \cellcolor{blue} &  & Myomeres \\ 
\Hline
 & \cellcolor{blue} 
    &  & \cellcolor{yellow} &  & Arches \\ 
\Hline
\end{NiceTabular}

\end{document}

You need several compilations (because nicematrix uses PGF/Tikz nodes under the hood).