You can override createArrowButton()
in BasicComboBoxUI
. BasicArrowButton
is a convenient starting point.
class ColorArrowUI extends BasicComboBoxUI {
public static ComboBoxUI createUI(JComponent c) {
return new ColorArrowUI();
}
@Override protected JButton createArrowButton() {
return new BasicArrowButton(
BasicArrowButton.SOUTH,
Color.cyan, Color.magenta,
Color.yellow, Color.blue);
}
}
Then install it.
JComboBox combo = new JComboBox();
combo.setUI(ColorArrowUI.createUI(combo));