* Set background color of the sheet tab
*
* @param colorIndex the indexed color to set, must be a constant from {@link IndexedColors}
*/
public void setTabColor(int colorIndex){
CTSheetPr pr = worksheet.getSheetPr();
if(pr == null) pr = worksheet.addNewSheetPr();
CTColor color = CTColor.Factory.newInstance();
color.setIndexed(colorIndex);
pr.setTabColor(color);
}