Swift 5 extension to add NSColor support to UserDefaults

UserDefaults+NSColor.swift

import Cocoa

extension UserDefaults {
    
    func set(_ color: NSColor, forKey: String) {
        if let data = try? NSKeyedArchiver.archivedData(withRootObject: color, requiringSecureCoding: false) {
            self.set(data, forKey: forKey)
        }
    }
    
    func color(forKey: String) -> NSColor? {
        guard
            let storedData = self.data(forKey: forKey),
            let unarchivedData = try? NSKeyedUnarchiver.unarchivedObject(ofClass: NSColor.self, from: storedData),
            let color = unarchivedData as NSColor?
        else {
            return nil
        }
        
        return color
    }
    
}

// get defaults instance
let defaults = UserDefaults.standard

// create a color
let mycolor = NSColor(red: 0.0, green: 0.5, blue: 0.8, alpha: 0.5)

// save the color
defaults.set(mycolor, forKey: "mycolor")

// read the color back. this returns an optional, may be nil
defaults.color(forKey: "mycolor")