Change UIButton BorderColor in Storyboard

I Set CornerRadius and BorderWidth for UIbutton in User Defined Runtime Attributes. Without adding layer.borderColor it works Well and Display border in black color. But when add layer.borderColor does not work(does not show border).

For Swift:

Swift 3:

extension UIView {

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(cgColor: layer.borderColor!)
        }
        set {
            layer.borderColor = newValue?.cgColor
        }
    }
}

Swift 2.2:

extension UIView {

    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(CGColor: layer.borderColor!)
        }
        set {
            layer.borderColor = newValue?.CGColor
        }
    }
}