Emacs -Q
Then:
(linum-mode 1)
(setq face-remapping-alist '((default . custom-invalid)))
Observe that the empty space in the left margin is white, rather than red. See attached screenshot.
The left (and presumably right) margins seem to use the default face, but fail to take `face-remapping-alist' into account.
It would not hurt to have a `margins' face, but even then, remapping should be observed.
This is an up to date build.
In GNU Emacs 24.3.50.4 (x86_64-apple-darwin13.0.0, NS apple-appkit-1265.00)
of 2013-12-14 on momo
Windowing system distributor `Apple', version 10.3.1265
Configured using:
`configure --with-ns'
