* Set text color.
* @param rgbStr - the desired color, in the hex form "RRGGBB".
*/
public void setColor(String rgbStr) {
CTRPr pr = run.isSetRPr() ? run.getRPr() : run.addNewRPr();
CTColor color = pr.isSetColor() ? pr.getColor() : pr.addNewColor();
color.setVal(rgbStr);
}