如何更改MFMessageComposeViewController的导航栏颜色？

#import <MessageUI/MessageUI.h>

- (void)sendMessage {
    if ([MFMessageComposeViewController canSendText]) {
        MFMessageComposeViewController *messageComposeVC = [[MFMessageComposeViewController alloc] init];
        messageComposeVC.messageComposeDelegate = self;
        
        // 更改导航栏颜色
        UINavigationBar *navigationBar = [messageComposeVC.navigationBar appearance];
        [navigationBar setBarTintColor:[UIColor yourColor]];
        [navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor yourColor]}];
        [navigationBar setTintColor:[UIColor yourColor]];
        
        // 设置短信内容和收件人等
        
        [self presentViewController:messageComposeVC animated:YES completion:nil];
    }
}

#pragma mark - MFMessageComposeViewControllerDelegate

- (void)messageComposeViewController:(MFMessageComposeViewController *)controller didFinishWithResult:(MessageComposeResult)result {
    [controller dismissViewControllerAnimated:YES completion:nil];
}