UIView* buttonView = [[UIView alloc] initWithFrame:CGRectMake(10, 0, 100, 40)];
    buttonView.backgroundColor = [UIColor clearColor];

    backButton = [[UIButton alloc] initWithFrame:CGRectMake(5, 5, 100, 30)];
    [backButton setBackgroundImage:[UIImage imageNamed:@"backbutton_100.png"] forState:UIControlStateNormal];
    [backButton addTarget:self  action:@selector(backAction:)  forControlEvents:UIControlEventTouchUpInside];
    [backButton setTitle:@"  All Customers" forState:UIControlStateNormal];
    backButton.titleLabel.font = [UIFont boldSystemFontOfSize:12];
    [buttonView addSubview:backButton];

    UIBarButtonItem* leftButton = [[UIBarButtonItem alloc] initWithCustomView:buttonView];
    self.navigationItem.leftBarButtonItem = leftButton;
    [leftButton release];

[backButton setTitleColor:[UIColor colorWithRed:0.3 green:0.6 blue:0.9 alpha:0.5]
//                                set 'alpha' to something less than 1. -----^^^
                 forState:UIControlStateNormal];