tabu: Alternating colors of rows

Question

Why does the following MWE not work as expected to make the row color alternate?

\documentclass{article}

\usepackage{tabularx,booktabs,tabu,amsmath,colortbl}
\usepackage[table]{xcolor}

\begin{document}

\begin{tabu} to \linewidth {@{}*3{X[c]}@{}}
    \taburowcolors [1] 2{gray!10 .. white}
    \toprule
    5 & 6 & 7\\
    5 & 6 & 7\\
    \bottomrule
\end{tabu}

\end{document}

Answer 1

The manual for the tabu package starts with the warning:

The tabu package patches internal commands of many packages and is liable to stop working if those internal interfaces change. Unfortunately the original author appears to be out of contact and the package had not been updated for some years.

It seems that this warning should be taken seriously when it comes to comes to adding background colour to the rows because the example code for \taburowcolors, which is on page 19 of the manual, does not compile for me.

You can achieve something something similar to what you want using a tabularx environment:

Note, however, that the booktabs package does not work particularly well with \rowcolors as the line heights do not match properly, as is already evident from the image above.

Here is the code:

\documentclass{article}

\usepackage{tabularx,amsmath,booktabs}
\usepackage[table]{xcolor}

\begin{document}

\rowcolors{2}{gray!10}{white}
\begin{tabularx}{\linewidth}{@{}*3{X}@{}}
    \toprule
    5 & 6 & 7\\
    5 & 6 & 7\\
    \bottomrule
\end{tabularx}

\end{document}