Component (JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) { if (value instanceof SplitterItem) { String label = ((SplitterItem)value).getText(); TitledSeparator separator = new TitledSeparator(label); separator.setBackground(UIUtil.getListBackground()); separator.setForeground(UIUtil.getListForeground()); return separator; } else { myRenderer.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus); myRenderer.revalidate(); return this; } }