Conditional formatting LaTeX tables depending on cell values

A package for generating conditional formatted LaTeX tables that extends the one proposed in a post by Siavoosh Payandeh Azad. I've just extended it with the command \gradientd for a divergent colormap. There are also several other solutions discussed in this stackexchange post. The example can be seen in Overleaf here.

The code for generating the table

\documentclass[table]{article}
\usepackage{highlight}

\begin{document}

% For a 2 color palette
% \gradientcell{cell_val}{min_val}{max_val}{colorlow}{colorhigh}{opacity} 

% For a 3 color/divergent palette
% \gradientcelld{cell_val}{min_val}{mid_val}{max_val}{colorlow}{colormid}{colorhigh}{opacity}

% Configure a shorthand macro

\newcommand{\g}[1]{\gradientcelld{#1}{-3}{0}{3}{red}{white}{green}{70}}

\begin{tabular}{l|ccccc}
{$\sigma$} &  40  &   80  & 100  &   200 &  800 \\
\hline
0  & \g{ 0.87} & \g{ 0.84} & \g{ 1.04} & \g{ 1.34} & \g{-4.30} \\
5  & \g{ 0.38} & \g{ 0.22} & \g{ 0.33} & \g{ 0.58} & \g{-2.18} \\
10 & \g{ 0.29} & \g{ 0.04} & \g{ 0.11} & \g{ 0.48} & \g{-0.67} \\
25 & \g{-0.05} & \g{-0.34} & \g{-0.39} & \g{-0.48} & \g{-0.53} \\
50 & \g{ 0.04} & \g{-0.18} & \g{-0.13} & \g{-0.08} & \g{ 0.11} \\
\end{tabular}

\end{document}

The package highlight.sty  implement these commands  

%% Siavoosh Payandeh Azad Jan. 2019
%% modified by Gabriele Facciolo Sep. 2021
\ProvidesPackage{highlight}[Cell background highlighting based on user data]
\RequirePackage{etoolbox}
\RequirePackage{pgf} % for calculating the values for gradient
\RequirePackage{xcolor} % enables the use of cellcolor make sure you have [table] option in the document class 

%======================================
% For a 2 color palette
% \gradientcell{cell_val}{min_val}{max_val}{colorlow}{colorhigh}{opacity} 
\newcommand{\gradientcell}[6]{
    % The values are calculated linearly between \midval and \maxval
    \ifdimcomp{#1pt}{>}{#3 pt}{\cellcolor{#5!100.0!#4!#6}#1}{
    \ifdimcomp{#1pt}{<}{#2 pt}{\cellcolor{#5!0.0!#4!#6}#1}{
         \pgfmathparse{int(round(100*(#1/(#3-#2))-(#2 *(100/(#3-#2)))))}
        \xdef\tempa{\pgfmathresult}
        \cellcolor{#5!\tempa!#4!#6}#1
    }}
 }
%======================================

%======================================
% For a 3 color/divergent palette
% \gradientcelld{cell_val}{min_val}{mid_val}{max_val}{colorlow}{colormid}{colorhigh}{opacity} 
\newcommand{\gradientcelld}[8]{
\xdef\lowvalx{#2}%
\xdef\midvalx{#3}%
\xdef\maxvalx{#4}%
\xdef\lowcolx{#5}%
\xdef\midcolx{#6}%
\xdef\highcolx{#7}%
\xdef\opacityx{#8}%
% The values are calculated linearly between \midval and \maxval
\ifdimcomp{#1pt}{>}{\maxvalx pt}{\cellcolor{\highcolx!100.0!\midcolx!\opacityx}#1}{
\ifdimcomp{#1pt}{<}{\midvalx pt}{%
\ifdimcomp{#1pt}{<}{\lowvalx pt}{\cellcolor{\midcolx!0.0!\lowcolx!\opacityx}#1}{
     \pgfmathparse{int(round(100*(#1/(\midvalx-\lowvalx))-(\lowvalx*(100/(\midvalx-\lowvalx)))))}%
    \xdef\tempa{\pgfmathresult}%
    \cellcolor{\midcolx!\tempa!\lowcolx!\opacityx}#1%
}}{
     \pgfmathparse{int(round(100*(#1/(\maxvalx-\midvalx))-(\midvalx*(100/(\maxvalx-\midvalx)))))}
    \xdef\tempb{\pgfmathresult}%
    \cellcolor{\highcolx!\tempb!\midcolx!\opacityx}#1%
}}
}
%======================================