import java.awt.Color;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.JTableHeader;
public class Main {
public static void main(String[] args) {
Integer[][] data = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
String[] cols = { "A", "B", "C" };
JTable table = new JTable(data, cols);
JTableHeader header = table.getTableHeader();
header.setBackground(Color.black);
header.setForeground(Color.yellow);
JOptionPane.showMessageDialog(null, new JScrollPane(table));
}
}