ios - UIModalPresentationFormSheet can't change superview background to clear

Question

I'm using UIViewController with UIModalPresentationFormSheet presentation style, then I try to present modal to this controller other with current context and Flip Horizontal transition style. But results looks like in an attachment...

I try to set superview.backgroundColor = [UIColor clearColor]; but any results... also I try to change background color of superview.layer, but have on effect