How to remove on press effect from a theme?

Question

I am modifying the Greybird theme for xfce, and there is something that I want to remove but I can't find where the code for it is located. I already figured out how to change the colors when the window 'tab' is active on panel, and so on, and all of that was so far located in $THEME/gtk-2.0/gtkrc and $THEME/gtk-2.0/apps/xfce-panel.rc. Now there is an effect in Greybird theme, when you press a launcher, or wifi indicator, or window on window list on panel, it kind of sinks in, or moves a little to bottom-right, giving an impression that a button was pressed. I want to remove that effect and I don't know where to look anymore. Can someone experienced in theming tell me where to look?

Answer 1

I found it by comparing with another theme which didn't have this effect. There are two lines in gtkrc file:

GtkButton       ::child-displacement-x          = 1
GtkButton       ::child-displacement-y          = 1

Setting these two to 0 removes the press effect.