Default DISPLAY of custom-set-faces SPECs

[Tassilo Horn]

Hi all,

I have some problems with customize-face.  I always fire up an emacs
instance with an X frame in the morning, and thereafter I use
emacsclient for both X (white bg, black fg) and terminals (black bg,
white fg).

Now, I customized some faces in an X frame (like changing the background
of hl-line face), and after opening a terminal frame I can see that I
cannot see anything: in the terminal frame, I have a white foreground on
a white background.

The reason is that emacs uses `t' as DISPLAY in the relevant SPEC of
`custom-set-faces'.  Since my terminal has only 8 colors according to
`list-colors-display' and the emacs defaults are pretty good in that
circumstances, I'd like to make all my face customizations only take
effect in X frames.  I did that by replacing `t' with `((type x))' in
all SPECs.

Is it possible to teach `customize-face' to use that as default value,
so that all my face configs apply only to X frames?

Bye,
Tassilo