It isn’t easy to safely enable HTML colors in the editor, but you can add some color by using Mathjax.
This code
$ \color{blue}blue $, $ \color{green}green $, $ \color{red}red $
produces this output:
\color{blue}blue , \color{green}green , \color{red}red
Scroll down to the “Math” section on this page for more information on Mathjax.