public static boolean isLafDark() {
		LookAndFeel lookAndFeel = UIManager.getLookAndFeel();
		return lookAndFeel instanceof FlatLaf && ((FlatLaf)lookAndFeel).isDark();
	}
Checks whether the current look and feel is dark.
flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java