Conditional Latex table: Cell value color based on its value

Question

I would like to create a conditional where values less than 7 are in red and values greater than or equal to 7 are in blue.

I would like a result like the one below:

Follows my MWE.

\documentclass[12pt,a4paper]{article}
\usepackage[brazil]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[pdftex]{color}
\usepackage{longtable}
\usepackage{spreadtab}

\begin{document}

\pagestyle{empty}

 \centering
  \begin{spreadtab}{{longtable}{c c c c c c}}
   \hline
    @ {\bf Number} & @ {\bf 1º Exam} & @ {\bf 2º Exam} & @ {\bf Mean} & @ {\bf Final} & @ {\bf Situation} \\
   \hline
    \rowcolor{gray!25}
        @ 18101610 & 7 & 8.5 & (b2+c2)/2 & - & \\
        @ 18103839 & 6 & 4.3 & (b3+c3)/2 & 7 & \\
    \rowcolor{gray!25}
        @ 18101547 & 5.4 & 3.5 & (b4+c4)/2 & 6 & \\
        @ 18100204 & 7 & 8 & (b5+c5)/2 & - & \\
    \rowcolor{gray!25}
        @ 14101294 & 9 & 10 & (b6+c6)/2 & - & \\
        @ 18101505 & 3.7 & 1.5 & (b7+c7)/2 & - & \\
   \hline
\end{spreadtab}

\end{document}

Other questions have already addressed this issue, but in my case the \usepackage[table]{xcolor} is conflicting with \usepackage{collcell,xfp}. The conditional is changing the color of all the cells, even the text is getting colored.

\documentclass[12pt,a4paper]{article}
\usepackage[brazil]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[pdftex]{color}
\usepackage{collcell, xfp}
\usepackage{longtable}
\usepackage{spreadtab}

\begin{document}

\newcommand{\fmtnum}[1]{%
  \ifnum\fpeval{#1 < 7} = 1
   \textcolor{red}{$#1$}%
  %\else
    %\ifnum\fpeval{#1 < 0.5} = 1
     %\textcolor{green}{$#1$}%
   \else
   \textcolor{blue}{$#1$}%
   %\fi
  \fi
}

\centering
 \begin{tabular}{ *{6}{>{\collectcell\fmtnum}c<{\endcollectcell}}}
  \hline
    {\bf Number} & {\bf 1º Exam} & {\bf 2º Exam} & {\bf Mean} & {\bf Final} & {\bf Situation} \\
   \hline
    \rowcolor{gray!25}
        18101610 & 1 & 2 & 1.5 &  & \\
        18103839 & 4 & 7.5 & 5.75 & 7 & \\
    \rowcolor{gray!25}
        18101547 & 5.4 & 3.5 & 4.45 & 6 & \\
        18100204 & 7 & 8 & 7.5 & - & \\
    \rowcolor{gray!25}
        14101294 & 9 & 10 & 9.5 & - & \\
        18101505 & 3.7 & 1.5 & 2.6 & - & \\
   \hline
\end{tabular}
\end{document}

Similar questions:

https://stackoverflow.com/questions/52123278/number-color-according-to-its-value-in-latex

https://tex.stackexchange.com/a/174360/187808

Automatic coloring of numbers according to size