UIColor extension to work with hex strings (Swift 4)

UIColor+Extensions.swift

//
//  UIColor+Extensions.swift
//  Roadmap
//
//  Created by Paul van Roosendaal on 19/06/2018.
//  Copyright © 2018 Roadmap. All rights reserved.
//

// Origin: https://gist.github.com/yannickl/16f0ed38f0698d9a8ae7

import UIKit

extension UIColor {
	
	convenience init(hexString: String) {
		let hexString = hexString.trimmingCharacters(in: .whitespacesAndNewlines)
		let scanner = Scanner(string: hexString)
		
		if hexString.hasPrefix("#") {
			scanner.scanLocation = 1
		}
		
		var color: UInt32 = 0
		scanner.scanHexInt32(&color)
		
		let mask = 0x000000FF
		let r = Int(color >> 16) & mask
		let g = Int(color >> 8) & mask
		let b = Int(color) & mask
		
		let red   = CGFloat(r) / 255.0
		let green = CGFloat(g) / 255.0
		let blue  = CGFloat(b) / 255.0
		
		self.init(red: red, green: green, blue: blue, alpha: 1)
	}
	
	var hexString: String {
		
		var r: CGFloat = 0
		var g: CGFloat = 0
		var b: CGFloat = 0
		var a: CGFloat = 0
		
		getRed(&r, green: &g, blue: &b, alpha: &a)
		
		let rgb: Int = (Int)(r * 255) << 16 | (Int)(g * 255) << 8 | (Int)(b * 255) << 0
		
		return String(format: "#%06x", rgb)
	}
}

Beware, this crashes on iPhone 5 and all the 32bit devices because Int means Int32 not Int64 on them.