How can configure MathJax to recognize textrm{} in equation when using textcolor?

Question

I'm trying to make an HTML page from LaTEX document that recently achieve it, I used the following mathjax, script configuration, after the head tag:

<script src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>    
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({
    extensions: ["tex2jax.js"],
    jax: ["input/TeX", "output/HTML-CSS"],

  tex2jax: {
    inlineMath: [ ['$','$'], ["\\(","\\)"] ],
    displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
    processEscapes: true
  },
    "HTML-CSS": { fonts: ["TeX"] }
  });
</script>
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({
    "HTML-CSS": { 
      styles: {".MathJax": {color: "#FF0000 ! important"}} 
    }
  });                 

  MathJax.Hub.Queue(
    ["resetEquationNumbers",MathJax.InputJax.TeX],
    ["PreProcess",MathJax.Hub],
    ["Reprocess",MathJax.Hub]
 );
</script>

When I try to write the following equation:

\[
\det A=|A|=\left\{
\begin{array}{ll}
-\textrm{fixation d'une  \textcolor{red}{ligne:}} i=\color{red}{p} \Rightarrow |A|=(-1)^{\color{red}{p}+j}\Delta_{\color{red}{p}j}\\
-\textrm{fixation d'une colonne:  } j=\color{red}{p} \Rightarrow |A|=(-1)^{\color{red}{p}+i}\Delta_{i\color{red}{p}}
\end{array}
\right.
\]

The command textcolor{red} doesn't work. What can I do it with MathJax to configure it in order to get a colorful text in equation?

This is the result of my compilation:

Answer 1

As per the documentation, MathJax does does not focus on textmode and only allows the following within its text-mode macros (\text{} etc): $ for re-entering math mode, \ref and \eqref.

So there is no way to get anything like \textcolor inside \text to work.

However, you can wrap \color around \text to color the text and thus you could define a custom macro \textwithcolor{red}{some text mode}, e.g., by using $\require{color}\newcommand{\textwithColor}[2]{\color{#1}{\text{#2}}} \textwithColor{red}{halleo}$.

You would still need to drop out of text mode to use it.

FWIW, there is an open issue for MathJax v3 to reconsider macros within text mode.