What should I do so that the length of the brackets remains constant when I color the table?

Question

\documentclass[a4paper,10pt]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
%\usepackage[table]{xcolor}
%\usepackage{colortbl}
%\usepackage{xcolor}
\usepackage{multirow}
\usepackage{graphicx}

\begin{document}

    \begin{table}[]
    \centering
    %\caption{}
    \vspace{\baselineskip}
    %\label{tab:my-table}
    \resizebox{\textwidth}{!}{%
        \begin{tabular}{cccccccccccccccc}
            \multicolumn{16}{c}{\textbf{\begin{tabular}[c]{@{}c@{}}LINE 1\end{tabular}}} \\
            \multicolumn{16}{c}{\downbracefill} \\
                \multicolumn{16}{c}{} \\
            \multicolumn{8}{c}{\textbf{\begin{tabular}[c]{@{}c@{}}LEFT LINE\end{tabular}}} &
            \multicolumn{8}{c}{\textbf{\begin{tabular}[c]{@{}c@{}}RIGHT LINE\end{tabular}}} \\
            \multicolumn{8}{c}{\downbracefill} & \multicolumn{8}{c}{\downbracefill} \\
                \multicolumn{16}{c}{} \\
            \hline
            \rowcolor{green}\multicolumn{1}{|c|}{--}&
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \rowcolor{yellow}\multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} \\ \hline
            \multicolumn{1}{{@{}c@{}}}{15} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{{@{}c@{}}}{8} &
            \multicolumn{1}{{@{}c@{}}}{7} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{{@{}c@{}}}{0} \\
        \end{tabular}%
    }
\end{table}
\end{document}

What I want to do is to color the cells. But when I use any coloring package, the brackets get shorter. Does anyone have suggestions?

Before:

After:

Answer 1

As documented in the colortbl documentation you need to balance the fill glue or use a higher order fill.

\documentclass[a4paper,10pt]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
%\usepackage[table]{xcolor}
\usepackage{colortbl}
\usepackage{xcolor}
\usepackage{multirow}
\usepackage{graphicx}

\begin{document}

    \begin{table}% [] means don't allow the table anywhere
    \centering
    %\caption{}
    \vspace{\baselineskip}
    %\label{tab:my-table}
 % don't distort tables   \resizebox{\textwidth}{!}{%
        \begin{tabular}{cccccccccccccccc}
            \multicolumn{16}{c}{\textbf{\begin{tabular}[c]{@{}c@{}}LINE 1\end{tabular}}} \\
            \multicolumn{16}{c}{\def\hfill{\hskip0pt plus 1filll\relax}\downbracefill} \\
                \multicolumn{16}{c}{} \\
            \multicolumn{8}{c}{\textbf{\begin{tabular}[c]{@{}c@{}}LEFT LINE\end{tabular}}} &
            \multicolumn{8}{c}{\textbf{\begin{tabular}[c]{@{}c@{}}RIGHT LINE\end{tabular}}} \\
          \multicolumn{8}{c}{\def\hfill{\hskip0pt plus 1filll\relax}\downbracefill} &
             \multicolumn{8}{c}{\def\hfill{\hskip0pt plus 1filll\relax}\downbracefill} \\
                \multicolumn{16}{c}{} \\
            \hline
            \rowcolor{green}\multicolumn{1}{|c|}{--}&
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} &
            \multicolumn{1}{c|}{--} \\ \hline
            \multicolumn{1}{{@{}c@{}}}{15} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{{@{}c@{}}}{8} &
            \multicolumn{1}{{@{}c@{}}}{7} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{c}{} &
            \multicolumn{1}{{@{}c@{}}}{0} \\
        \end{tabular}%
%    }
\end{table}
\end{document}