It\'s been so hard to find any clear information about how to create icons with two colors (facebook -white and blue-, google- white and red.....). The customer wants to be
The example in the link you provided is quite clear. You create 2 SVGs. One for each of the 2 colors in your icon, and add them as two different characters to the font. (\e006 and \e0007 in the example)
Then you use both the :before
selector and the :after
selector to add the characters using different colors.
Each selector is using a different character and a different color.
The letter-spacing: -1
causes the characters to overlap.
I took their jsfiddle example and fixed it to work with font awesome: http://jsfiddle.net/p44zf3se/
Update
I am not sure why my previous answer was not enough, but here is another example. I can't upload it to jsfiddle because the font cannot be served from another site. So just take the html below + download the free IcoMoon font from: http://github.com/Keyamoon/IcoMoon-Free/raw/master/Font/IcoMoon-Free.ttf