TextCollectionView-Demo_6.swift

private func adaptToUserInterfaceStyle() {
    label.backgroundColor = UIColor.brown.withAlphaComponent(0.3)
    label.textColor = UIColor.brown
    if #available(iOS 12.0, *) {
        if contentView.traitCollection.userInterfaceStyle == .dark {
            label.backgroundColor = UIColor.cyan.withAlphaComponent(0.3)
            label.textColor = UIColor.cyan
        }
    }
}