It would be great if the Coolite.Ext.TriggerComboBox (or Ext.form.ComboBox) were extended to apply an additional style to the combobox_container while the combobox's dropdown (x-combo-list) is visible ... perhaps something like 'x-combo-open'?

This additional style on the combobox_container (not the x-combo-list) would allow for better styling of custom comboboxes.