Change navigation bar border color

NavigationBar.swift

import UIKit

class NavigationBar: UINavigationBar {

	// MARK: - Properties

	var borderColor: UIColor? {
		set {
			borderView.backgroundColor = newValue
		}

		get {
			return borderView.backgroundColor
		}
	}

	private let borderView: LineView = {
		let view = LineView()
		view.translatesAutoresizingMaskIntoConstraints = false
		return view
	}()


	// MARK: - Initializers

	override init(frame: CGRect) {
		super.init(frame: frame)

		shadowImage = UIImage()

		addSubview(borderView)

		NSLayoutConstraint.activateConstraints([
			borderView.topAnchor.constraintEqualToAnchor(bottomAnchor),
			borderView.leadingAnchor.constraintEqualToAnchor(leadingAnchor),
			borderView.trailingAnchor.constraintEqualToAnchor(trailingAnchor)
		])
	}

	required init?(coder aDecoder: NSCoder) {
		fatalError("init(coder:) has not been implemented")
	}
}

What is LineView?

Use a UIView instead on a "LineView"