The solution in the post https://tex.stackexchange.com/a/100625 is highly efficient. Unfortunately it can not be used with unicode-math, which erases the individualized symbol colors. While unicode-math does allow individual symbol coloring via
\setmathfont, if too many symbols are independently colored in this way, the source will not compile.
Is there any way to make the
\colorizemath code (linked above) compatible with unicode-math ?