After installing the NS FontAwesome Pro installation package you must head over to your Plugin Manager and enable the NS FontAwesome and NS FontAwesome Editor Button plugins.

If you have the free version installed you should disable it or uninstall it as it's no longer needed.

Configuration / Presets

Open up the NS FontAwesome Editor Button plugin and click on the Advanced Tab.

In here you can set hex colors and font sizes that will be available for selection when you insert icons. The presets help avoid the use of in-line styling in your HTML. Instead of setting size and color via the editor the plugin will insert CSS classes using the colors and sizes you have in the presets.

Colors

Be sure to use complete hex codes or valid HTML color names. When using hex codes you must include the #. You can click on the little colored block on the right of each field to open a color picker.

Font Sizes

You can insert sizes in PX, EM or REM. Be sure to include the format after the integer. E.g. 1.5em or 24px.