This is my MWE
\documentclass{standalone}
\usepackage{tkz-tab}
\pagecolor{yellow}
\begin{document}
\begin{tikzpicture}[node style/.style={fill opacity=0,text opacity=1}]
\tkzTabInit[espcl=1.75]{$x$/.5,$f'(x)$/.7,$f(x)$/1.5}{$-\infty$,$-2$,$-1$,$0$,$+\infty$}
\tkzTabLine{,+,z,-,d,-,z,+,}
\tkzTabVar{-/$-\infty$,+/$-3$,-D+/$-\infty$/$+\infty$,-/$1$,+/$+\infty$}
\end{tikzpicture}
\end{document}
How can I set the double
opacity to zero. Note that its default color is white.