code: @Override
      protected void paintComponent(Graphics g) {
          SeaGlassPainter painter = (SeaGlassPainter) UIManager.get("TableHeader:\"TableHeader.renderer\"[Enabled].backgroundPainter");
  
          if (painter != null) {
  
              Graphics2D g2d = (Graphics2D) g;
  
              painter.paint(g2d, this, getWidth() + 1, getHeight());
          }
      }
docs: Paint the component using the Nimbus Table Header Background Painter
  
  @param g the Graphics context to paint with.