BackBarButtonItem in iOS8 can't change tintColor?

Question

I have called [[UIBarButtonItem appearance] setTintColor:XXX] in my AppDelegate.

But I find the backBarButtonItem doesn't change its tintColor when the other barItems have changed to right color.

Is't a bug only in iOS8 beta5?

Answer 1

I found the answer.

[[UINavigationBar appearance] setTintColor:XXXXX]]