property wrapper for codable color hex string

UIColorHexString.swift

import UIKit

@propertyWrapper
struct UIColorHexString: Codable {
    private var stringValue: String
    
    var wrappedValue: UIColor {
        get { UIColor(hexString: stringValue) }
        set { stringValue = newValue.hexString }
    }
    
    init(_ color: UIColor) {
        self.stringValue = color.hexString
    }
    
    init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        stringValue = try container.decode(String.self)
    }
    
    func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        try container.encode(stringValue)
    }
}