Apache-POI：单元格背景色不起作用

我想一般的配置CellStyles为在格式化HSSFCells使用Apache-POI 3.11。

这是代码的可运行示例。正确应用了粗体和边框格式。问题在于背景和前景颜色。

我在做什么错的任何线索？

public class TestSO {

private final static short 
        MY_LIGHT_BLUE=100,
        MY_DARK_BLUE=101,
        MY_BLACK=102,
        MY_WHITE=103;

public static void main(String[]args) throws Exception{
    HSSFWorkbook workbook = new HSSFWorkbook();
    setPallete( workbook.getCustomPalette() );

    HSSFFont fontNormal = workbook.createFont();
    fontNormal.setFontHeightInPoints((short)11);
    fontNormal.setFontName("Calibri");
    HSSFFont fontBold = workbook.createFont();
    fontBold.setFontHeightInPoints((short)11);
    fontBold.setFontName("Calibri");
    fontBold.setBold(true);


    HSSFCellStyle titleStyle = workbook.createCellStyle();
    titleStyle.setFillBackgroundColor(MY_DARK_BLUE);
    titleStyle.setFillForegroundColor(MY_WHITE);
    titleStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    titleStyle.setFont(fontBold);
    setTopBotBorder(titleStyle);

    HSSFCellStyle fpStyle = workbook.createCellStyle();
    fpStyle.setFillBackgroundColor(MY_LIGHT_BLUE);
    fpStyle.setFillForegroundColor(MY_BLACK);
    fpStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    fpStyle.setFont(fontNormal);
    setTopBotBorder(fpStyle);

    HSSFSheet sheet = workbook.createSheet("Leyenda");

    HSSFCell cell;

    cell = sheet.createRow( 1 ).createCell( 1 );
    cell.setCellValue("TitleStyle");
    cell.setCellStyle(titleStyle);

    cell = sheet.createRow( 2 ).createCell( 1 );
    cell.setCellValue("FpStyle");
    cell.setCellStyle(fpStyle);

    sheet.autoSizeColumn(1);

    try (FileOutputStream fos = new FileOutputStream( new File("TestWB.xls") )) {
        workbook.write( fos );
    }
}  

private static void setPallete( HSSFPalette pallete ){
    pallete.setColorAtIndex(MY_LIGHT_BLUE, (byte)189,(byte)215,(byte)238);
    pallete.setColorAtIndex(MY_DARK_BLUE, (byte)32,(byte)55,(byte)100);
    pallete.setColorAtIndex(MY_BLACK, (byte)0,(byte)0,(byte)0);
    pallete.setColorAtIndex(MY_WHITE, (byte)255,(byte)255,(byte)255);
}

private static void setTopBotBorder( CellStyle style ){
    style.setBorderBottom(CellStyle.BORDER_THIN);
    style.setBottomBorderColor(MY_BLACK);
    style.setBorderTop(CellStyle.BORDER_THIN);
    style.setTopBorderColor(MY_BLACK);
}

}

这是Excel文件的输出：

提前致谢。