Subject: bug#4381: 23.1.50; Cocoa Emacs: face background for 'region set in ns-win.el after .emacs

From: Stefan Monnier <[email-masked]>
Date: Wed, 23 Sep 2009 18:44:08 -0400

>>> (custom-set-faces '(region ((t (:background "ns_selection_color")))))
>> Why not change faces.el directly?

> I guess I'd prefer to remove this feature completely over hacking into
> faces.el.

Your call, but if you want to change the default value of the `region'
face, it should be done directly in faces.el.

> Colors there are defined for dark and light backgrounds, which
> is not supported by the NS implementation.

Why isn't it supported?

> It would be nice to allow the default system-wide selection color to
> be  used under NS, but I guess if this is not being implemented on GTK
> /  etc. it is not considered important by Emacs users.

IIUC it is supported under w32 (also be defining special color names),
so you may want to check what they do there.  I do not know if they set
the faces to use those by default.
BTW, it might be a good idea to try and use the same special color names
whenever possible.
There's no such support under Gtk currently, AFAIK, but I don't think
it's because we don't want it, but because nobody wrote the code for it yet.

        Stefan