This is an "alternative" colorization to math4.  If you want to provide
multiple themes to your users you should follow this as an example.

Everything except for the math4-overrides.js, math4-overrides.css,
_theme-colors.scss, and _theme-overrides.scss files should be links pointing
back to the corresponding files in math4.  This will make it so that all your
themes will automatically get updates.  All of your changes should be in the
listed override files.