tonini/alchemist.el — pull request #12 by pragdave (2014-11-03 00:34:02+00:00)
Title: Rather than have a special modeline element 

(which actually gets lost on my narrow display), change the face of the Elixir major mode itself.

To try this, run a mix command with some Elixir buffers visible. The mode name "Elixir" should change color in all buffers in Elixir mode.