Not to my knowledge, the button inherits the tint color of the navigationBar. What you can do is set a customView for the navigationItem:
This is how you set it with one of the SDK's buttons:
UIBarButtonItem *shareButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(shareButtonHandler:)];
[self.navigationItem setRightBarButtonItem:shareButton];
[shareButton release];
Instead you can do it like this:
UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"yourImage.png" style:UIBarButtonItemStyleBordered target:self action:@selector(customButtonHandler:)]];
To use an image you made in photoshop etc.
There is als an initWithCustomView:UIView
or initWithTitle:NSString
you can use.
Sorry no "one-line solution" :)