code: private void setSeriesStyles() {
  
      SeriesColorMarkerLineStyleCycler seriesColorMarkerLineStyleCycler =
          new SeriesColorMarkerLineStyleCycler(
              getStyler().getSeriesColors(),
              getStyler().getSeriesMarkers(),
              getStyler().getSeriesLines());
      for (BubbleSeries series : getSeriesMap().values()) {
  
        SeriesColorMarkerLineStyle seriesColorMarkerLineStyle =
            seriesColorMarkerLineStyleCycler.getNextSeriesColorMarkerLineStyle();
  
        if (series.getLineStyle() == null) { // wasn't set manually
          series.setLineStyle(seriesColorMarkerLineStyle.getStroke());
        }
        if (series.getLineColor() == null) { // wasn't set manually
          series.setLineColor(seriesColorMarkerLineStyle.getColor());
        }
        if (series.getFillColor() == null) { // wasn't set manually
          series.setFillColor(seriesColorMarkerLineStyle.getColor());
        }
      }
    }
docs: set the series color based on theme