Color setting of GTK-programs

[Setyo Nugroho <setyo.nugroho@web.de>]

Hi all, 

Due some unknown reasons( I have forgotten which programs I
clicked), all GTK-based programs' theme colors have changed.. 

I do NOT have gnome installed. I use a.o. gdm, gnumeric, sylpheed-claws.
So I think the setting must lie somewhere in a GTK's shared library. Is it correct?
The most painful thing is the colors of sylpheed-claws in particular are very poor now. 

How to reset these color settings? Should I install gnome first in order
to change these settings? I use kde3.0.3 and now prefer icewm. Does
someone have experience whether installing gnome 2.0 in coexistence with
others (kde & icewm) does not create another problem?

Any help would highly be appreciated.

Regards,
Setyo Nugroho