Re: customize-themes doesn't allow backquote or :inherit

[Yavuz]

Thinking a bit laterally, there are 2 alternate mechanisms that
could help (at the loss of some flexibility):

1. There are named colors, such as "royal blue" that one can use
instead of "#RRGGBB" format. If it were possible to user-define
more, that would be a solution.

2. There is the :inherit keyword that I couldn't get to work the
way I thought it would--allow the designer to define any face
attribute (and not just a color) once using a virtual face, and
then reuse it multiple times:

(custom-theme-set-faces 'mytheme
  '(highlighted-fg ((t (:foreground "#123456" :weight bold))))
  ...
  '(font-lock-error ((t (:inherit highlighted-fg) ...)


There is also a separate problem with saving a user-defined theme
for future sessions in any other directory than .emacs.d. I save
them in .emacs.d./themes, and set custom-theme-directory to it in
my customization file. Then I can interactively select it using
M-x customize-themes, and save it for future sessions (the name
gets saved into the .emacs.d/custom.el), but when emacs is
restarted, it cannot find the theme, presumably because custom.el
is loaded before the my customization file. Standard themes work
fine.