../GtkList is a deprected widget. Unfortunately it is still in use in some places that either use it or the ../GtkCombo widget. One place for example is the gnome-panel run dialog.
1. Drawing
The GtkList has items of the class ../GtkListItem. These list items will draw the background if they are selected using a flat_box. The state is of course SELECTED, detail string is "listitem" and the shadow is ETECHED_OUT. The default background is base[NORMAL] (each of them has their own X window, which means no transparency, etc.)
2. Problems
The ../GtkListItem contains a normal ../GtkLabel widget. This label draws the text with the fg[] colors instead of the text[] colors which would be more appropriate on the base[NORMAL] background.
You can work around this problem with a match similar to the following one:
widget_class "*<GtkListItem>*" style "list-item"