How to change the colors of a segment in a UISegmentedControl in iOS 13?

Question

A UISegmentedControl has a new appearance in iOS 13 and existing code to alter the colors of the segmented control no longer work as they did.

Prior to

Answer 1

Expanding a little bit on Jonathan answer in case you don't want round corners

extension UISegmentedControl {
    /// Tint color doesn't have any effect on iOS 13.
    func ensureiOS12Style(roundCorner: Bool = true) {
        if #available(iOS 13, *) {
            let tintColorImage = UIImage(color: tintColor)
            // Must set the background image for normal to something (even clear) else the rest won't work
            setBackgroundImage(UIImage(color: backgroundColor ?? .clear), for: .normal, barMetrics: .default)
            setBackgroundImage(tintColorImage, for: .selected, barMetrics: .default)
            setBackgroundImage(UIImage(color: tintColor.withAlphaComponent(0.2)), for: .highlighted, barMetrics: .default)
            setBackgroundImage(tintColorImage, for: [.highlighted, .selected], barMetrics: .default)
            setTitleTextAttributes([.foregroundColor: tintColor, NSAttributedString.Key.font: UIFont.systemFont(ofSize: 13, weight: .regular)], for: .normal)
            setDividerImage(tintColorImage, forLeftSegmentState: .normal, rightSegmentState: .normal, barMetrics: .default)

            if !roundCorner {
                layer.masksToBounds = false

                let borderView = UIView()
                borderView.layer.borderWidth = 1
                borderView.layer.borderColor = UIColor.black.cgColor
                borderView.isUserInteractionEnabled = false
                borderView.translatesAutoresizingMaskIntoConstraints = false

                addSubview(borderView)

                NSLayoutConstraint(item: borderView, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
                NSLayoutConstraint(item: borderView, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier: 1, constant: 0).isActive = true
                NSLayoutConstraint(item: borderView, attribute: .width, relatedBy: .equal, toItem: self, attribute: .width, multiplier: 1, constant: 0).isActive = true
                NSLayoutConstraint(item: borderView, attribute: .height, relatedBy: .equal, toItem: self, attribute: .height, multiplier: 1, constant: 0).isActive = true
            }
        }
    }
}