private static void patchGtkDefaults(UIDefaults defaults) { if (!UIUtil.isUnderGTKLookAndFeel()) return; Map<String, Icon> map = ContainerUtil.newHashMap( Arrays.asList( "OptionPane.errorIcon", "OptionPane.informationIcon", "OptionPane.warningIcon", "OptionPane.questionIcon"), Arrays.asList( AllIcons.General.ErrorDialog, AllIcons.General.InformationDialog, AllIcons.General.WarningDialog, AllIcons.General.QuestionDialog)); // GTK+ L&F keeps icons hidden in style SynthStyle style = SynthLookAndFeel.getStyle(new JOptionPane(""), Region.DESKTOP_ICON); for (String key : map.keySet()) { if (defaults.get(key) != null) continue; Object icon = style == null ? null : style.get(null, key); defaults.put(key, icon instanceof Icon ? icon : map.get(key)); } Color fg = defaults.getColor("Label.foreground"); Color bg = defaults.getColor("Label.background"); if (fg != null && bg != null) { defaults.put("Label.disabledForeground", UIUtil.mix(fg, bg, 0.5)); } }