Not sure if we want this, but I've noticed it mentioned on "Blender Today" a couple of times.
This patch allows users to set custom colors for the "Face Orientation", rather than have it always set on red and blue:
I find it a little cool that you could set something bold and bright for the inward faces but select something completely transparent for outward-facing if you like.
Not sure who to set for code review, so not setting one for now.