import java.awt.*;
import javax.swing.*;

public class Graph extends JPanel {
	public Graph() {
		setPreferredSize(new Dimension(200, 105));
	}

	@Override
	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		int[] is = {10, 4, 6, 2, 9, 1};
		Color[] cs = {Color.RED, Color.BLUE};
		int scale = 15;
		int i, n = is.length;

		for (i = 0; i < n; i++) {
			g.setColor(cs[i % cs.length]);
			g.fillRect(0, i * scale, is[i] * scale, scale);
		}
	}

	public static void main(String[] args) {
		SwingUtilities.invokeLater(() -> {
			JFrame frame = new JFrame("");
			frame.add(new Graph());
			frame.pack();
			frame.setVisible(true);
			frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		});
	}
}