colorV2

The colorV2 extension defines the \color macro to be the non-standard macro that is the default in MathJax version 2, namely, it takes two arguments, one the name of the color (or an HTML color of the form #RGB or #RRGGBB), and the second the math to be colored. This is in contrast to the standard LaTeX \color command, which is a switch that changes the color of everything that follows it.

This extension is not loaded automatically when the autoload extension is used. To load the color extension explicitly, add '[tex]/color' to the load array of the loader block of your MathJax configuration, and add 'color' to the packages array of the tex block.

window.MathJax = {
  loader: {load: ['[tex]/colorV2']},
  tex: {packages: {'[+]': ['color']}}
};

or, use \require{colorV2} in a TeX expression to load it dynamically from within the math on the page, if the require extension is loaded.

Alternatively, you can configure the autoload package to load colorV2 when \color is used rather than the (LaTeX-compatible) color extension:

window.MathJax = {
  tex: {
    autoload: {
      color: [],            // don't autoload the color extension
      colorV2: ['color']    // autoload colorV2 on the first use of \color
    }
  }
};