setBackground(new color()); in java does not understand the given RGB value

I have a program with some gui, on the JFrame I set,

 setBackground( new Color(107, 106, 104) );

[The problem] It gives a greyish color, but not the right one! 
If I check the gui's color in Photo Shop, it gives me the RGB 
values (126, 125, 123)

you can not set setBackground for JFrame, this is only possible for ContentPane, for example

JFrame#getContentPane.setBackground(new Color(107, 106, 104));

EDIT

from code

import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class Check extends JFrame {

    private static final long serialVersionUID = 1L;

    public void makeUI() {
        JFrame f = new JFrame();
        f.getContentPane().setBackground(new Color(107, 106, 104));
        f.setDefaultCloseOperation(EXIT_ON_CLOSE);
        f.setSize(new Dimension(300, 200));
        f.setVisible(true);
    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Check().makeUI();
            }
        });
    }
}