Default Generater for JProgressBar (Colour setter not working on MacOS)

Bar.java

		UIManager.put("ProgressBar.selectionBackground", Color.red);
		UIManager.put("ProgressBar.selectionForeground", Color.red);
		UIManager.put("ProgressBar.foreground", Color.red);
		UIManager.put("ProgressBar.background", Color.red);

    		JProgressBar bar = new JProgressBar();
		bar.setMaximum(50);
		bar.setMinimum(0);

		bar.setBounds(30, 118, 235, 41);

		bar.setValue(n);
		bar.setString(bar.getValue() + "/" + bar.getMaximum() + " HP");
		bar.setStringPainted(true);

		
		frame.getContentPane().add(bar);