A DESCRIPTION OF THE PROBLEM :
It seems that on Linux colors with an alpha transparency are painted incorrectly:

https://imgur.com/N1XuWCp

It may be related to this existing issue,
but I decided to report another bug just in case:
https://bugs.openjdk.java.net/browse/JDK-8204931

Painting off-screen is not affected (e.g. drawing to BufferedImage)

REGRESSION : Last worked in version 10.0.1

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Colors like in previous versions
ACTUAL -
Glitched colors

---------- BEGIN SOURCE ----------
import java.awt.*;
import javax.swing.*;

public class Test extends JFrame {

Test() {
JPanel p = new JPanel() {
@Override
protected void paintComponent(Graphics graphics) {
Graphics2D g = (Graphics2D)graphics.create();

g.setColor(Color.WHITE);
g.fillRect(0, 0, getWidth(), getHeight());

g.setColor(Color.RED);
g.fillRect(200, 200, 200, 200);

g.setComposite(AlphaComposite.SrcOver.derive(0.5f));

g.setColor(new Color(133, 156, 178));
g.fillRect(100, 100, 200, 200);

g.setColor(Color.BLACK);
g.fillRect(300, 300, 200, 200);

g.setColor(Color.GREEN);
g.fillRect(300, 100, 200, 200);

g.dispose();
}
};
add(p);

setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(800, 600);
setVisible(true);
}

public static void main(String... args) {
SwingUtilities.invokeLater(Test::new);
}

}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Works OK with -Dsun.java2d.xrender=false option

FREQUENCY : always