Re: master 11f10dc0d0b: Update etc/rgb.txt from X.Org upstream

[Stefan Kangas <stefankangas@gmail.com>]

Po Lu <luangruo@yahoo.com> writes:

> At any rate, you've introduced several colors (those named ``web'' and
> ``x11'') that are only available under a subset of the systems we
> support.  So let's return to the old version of rgb.txt, lest packages
> begin to use them and suffer the portability ramifications thereof.

While using portable colors is a concern, it seems orthogonal.  X.Org
ships with these colors, and as things stand, nothing is stopping them
from being used.  We could perhaps recommend against using them, and not
much else.

> For reference, on the computer I type this from:
>
>   (x-color-values "web Green")
>
> returns nil.  The X server is:
>
> Window system distributor: 'Sun Microsystems, Inc.', version 11.0.6620

While the potential issues for Solaris users are understood, I believe
we should weigh that against other platforms.

Reverting will mean that these colors won't work for users on some of
our most commonly used platforms.  That's all.  Is it good practice to
leave such things broken on some platforms, in the hope that it will be
enough to provoke Emacs Lisp developers to fix it on some others?