Browser: IE 11 (looks like it's not working in other browser too)
https://codepen.io/anon/pen/YQdqLa?editors=0010#0
Repro:
Expected:
-word that was selected changes color
Actual:
-nothing changes about the text color.
This is not a Quill JS issue

You need to whitelist 'color' in the enabled format list, or remove the prop to enable the default set (which is currently everything).
Most helpful comment
You need to whitelist 'color' in the enabled format list, or remove the prop to enable the default set (which is currently everything).