You can configure your application to use resources on GTK+ and X11/Motif. (This was already true on Motif, but is now documented.)
An example showing how to make a CAPI GUI configurable by GTK+ resources is in
examples/capi/elements/gtk-resources.lisp
.
Example resource files are in
examples/gtk/
.
For more information see the sections "Matching resources" in the
LispWorks CAPI User Guide
and the description of
widget-name
for
capi:element
in the
LispWorks CAPI Reference Manual
.