private static Paint createTransparentCheckeredPaint(Color color, int checkerSize) {
    int s = checkerSize;
    BufferedImage bufferedImage = new BufferedImage(2 * s, 2 * s, BufferedImage.TYPE_INT_ARGB);

    Graphics2D g2 = bufferedImage.createGraphics();
    g2.setRenderingHint(
        RenderingHints.KEY_ANTIALIASING, // Anti-alias!
        RenderingHints.VALUE_ANTIALIAS_ON);

    Color c1 = DataStructureUtils.setColorAlpha(color, (int) (color.getAlpha() * .8));
    Color c2 = DataStructureUtils.setColorAlpha(color, (int) (color.getAlpha() * .2));
    g2.setStroke(new BasicStroke(0));
    g2.setPaint(c2);
    g2.setColor(c2);
    g2.fillRect(0, 0, s, s);
    g2.fillRect(s, s, s, s);
    g2.setPaint(c1);
    g2.setColor(c1);
    g2.fillRect(0, s, s, s);
    g2.fillRect(s, 0, s, s);

    // paint with the texturing brush
    Rectangle2D rect = new Rectangle2D.Double(0, 0, 2 * s, 2 * s);
    return new TexturePaint(bufferedImage, rect);
  }
 @Override
 public Paint getItemOutlinePaint(int seriesIdx, int valueIdx) {
   if (getFormatDelegate().isItemSelected(seriesIdx, valueIdx)) {
     return super.getItemOutlinePaint(seriesIdx, valueIdx);
   } else {
     return DataStructureUtils.setColorAlpha(Color.LIGHT_GRAY, 20);
   }
 }
  private static void configureXYDifferenceRenderer(
      FormattedXYDifferenceRenderer renderer,
      ValueSource valueSource,
      PlotConfiguration plotConfiguration) {
    renderer.setBaseToolTipGenerator(new StandardXYToolTipGenerator());
    SeriesFormat seriesFormat = valueSource.getSeriesFormat();
    DimensionConfig domainConfig = valueSource.getDomainConfig();
    DimensionConfig colorDimensionConfig =
        plotConfiguration.getDimensionConfig(PlotDimension.COLOR);
    DimensionConfig shapeDimensionConfig =
        plotConfiguration.getDimensionConfig(PlotDimension.SHAPE);

    int seriesCount = 1; // valueSource.getSeriesDataForAllGroupCells().groupCellCount();

    // Loop all series and set series format.
    // Format based on dimension configs will be set later on in initFormatDelegate().
    for (int seriesIdx = 0; seriesIdx < seriesCount; ++seriesIdx) {
      // configure linestyle
      if (seriesFormat.getLineStyle() == LineStyle.NONE) {
      } else {
        renderer.setSeriesStroke(seriesIdx, seriesFormat.getStroke(), false);
      }

      // configure series shape if necessary
      if (!SeriesFormat.calculateIndividualFormatForEachItem(domainConfig, shapeDimensionConfig)) {
        if (seriesFormat.getItemShape() != ItemShape.NONE) {
          renderer.setSeriesShape(seriesIdx, seriesFormat.getItemShape().getShape());
        } else {
        }
      }

      // configure series color if necessary
      if (!SeriesFormat.calculateIndividualFormatForEachItem(domainConfig, colorDimensionConfig)) {
        Color itemColor = seriesFormat.getItemColor();
        Color halfTransparentPaint =
            DataStructureUtils.setColorAlpha(itemColor, itemColor.getAlpha() / 2);

        renderer.setSeriesPaint(0, halfTransparentPaint);
        renderer.setSeriesFillPaint(0, halfTransparentPaint);
        renderer.setPositivePaint(halfTransparentPaint);
        renderer.setNegativePaint(
            new Color(
                255 - itemColor.getRed(),
                255 - itemColor.getGreen(),
                255 - itemColor.getBlue(),
                itemColor.getAlpha() / 2));
      }
      renderer.setSeriesOutlinePaint(seriesIdx, PlotConfiguration.DEFAULT_SERIES_OUTLINE_PAINT);
    }
  }