Swift 4和4.2版本:

 self.navigationController.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.green]

可以在appdelegate文件中使用此方法，并可以在每个视图中使用

+(UILabel *) navigationTitleLable:(NSString *)title
{
CGRect frame = CGRectMake(0, 0, 165, 44);
UILabel *label = [[[UILabel alloc] initWithFrame:frame] autorelease];
label.backgroundColor = [UIColor clearColor];
label.font = NAVIGATION_TITLE_LABLE_SIZE;
label.shadowColor = [UIColor whiteColor];
label.numberOfLines = 2;
label.lineBreakMode = UILineBreakModeTailTruncation;    
label.textAlignment = UITextAlignmentCenter;
[label setShadowOffset:CGSizeMake(0,1)]; 
label.textColor = [UIColor colorWithRed:51/255.0 green:51/255.0 blue:51/255.0 alpha:1.0];

//label.text = NSLocalizedString(title, @"");

return label;
}

要设置标题的字体大小，我使用了以下条件..也许对任何人都有帮助

if ([currentTitle length]>24) msize = 10.0f;
    else if ([currentTitle length]>16) msize = 14.0f;
    else if ([currentTitle length]>12) msize = 18.0f;

方法一，设置为IB:

方法二，一行代码:

navigationController?.navigationBar.barTintColor = UIColor.blackColor()

self.navigationItem.title=@"Extras";
[self.navigationController.navigationBar setTitleTextAttributes: [NSDictionary dictionaryWithObjectsAndKeys:[UIFont fontWithName:@"HelveticaNeue" size:21], NSFontAttributeName,[UIColor whiteColor],UITextAttributeTextColor,nil]];

根据Steven Fisher的回答，我写了这样一段代码:

- (void)setTitle:(NSString *)title
{
    [super setTitle:title];
    UILabel *titleView = (UILabel *)self.navigationItem.titleView;
    if (!titleView) {
        titleView = [[UILabel alloc] initWithFrame:CGRectZero];
        titleView.backgroundColor = [UIColor clearColor];
        titleView.font = [UIFont boldSystemFontOfSize:20.0];
        titleView.shadowColor = [UIColor colorWithWhite:0.0 alpha:0.5];

        titleView.textColor = [UIColor yellowColor]; // Change to desired color

        self.navigationItem.titleView = titleView;
        [titleView release];
    }
    titleView.text = title;
    [titleView sizeToFit];
}

这段代码的优点，除了正确地处理帧，是如果你改变你的控制器的标题，自定义标题视图也会得到更新。无需手动更新。

另一个很大的优势是，它使得启用自定义标题颜色非常简单。您所需要做的就是将这个方法添加到控制器中。