navigationBar.tintColor无效时换个方式

使用

self.navigationController.navigationBar.tintColor = [UIColor whiteColor];

无效时可以试试下面这个

NSMutableDictionary *att = [NSMutableDictionary dictionary];

att[NSForegroundColorAttributeName] = [UIColor whiteColor];

[self.navigationController.navigationBar setTitleTextAttributes:att];