The default color and other attributes for each CAPI pane on X11/Motif is computed as an X resource using the symbol name of the pane's class. Therefore obtaining the correct X resources depends on the application containing these symbol names.
Symbol names are removed at delivery level 5, but you can retain specific names in the delivered image by passing a list of the class names to
as the value of the keyword argument :keep-symbol-names.
LispWorks Delivery User Guide - 13 Dec 2011