/indra/newview/skins/default/xui/en/widgets/panel.xml

 1<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 2<!-- Optional parameters:
 3  border - show border around panel
 4  bg_opaque_image - image name for "in-front" panel look
 5  bg_alpha_image - image name for "in-back" or transparent panel look
 6-->
 7<panel name="panel"
 8       bg_opaque_color="PanelFocusBackgroundColor"
 9       bg_alpha_color="PanelDefaultBackgroundColor"
10       bg_opaque_image_overlay="White"
11       bg_alpha_image_overlay="White"
12       background_visible="false"
13       background_opaque="false"
14       chrome="false"
15       accepts_badge="true"/>