How to update the color of section title without uitableview reloadData

I'm using willDisplayHeaderView to change the color of section title:

- (void)tableView:(UITableView *)tableView willDisplayHeaderView:(UIView *)view forSection:(NSInteger)section {

    UITableViewHeaderFooterView *header = (UITableViewHeaderFooterView *)view;
    header.textLabel.textColor = [UIColor grayColor];
}

Now, I want to update the color of a section title, how to do it without [tableview reloadData]?

via Chebli Mohamed