An extension to create custom colours and use hex values.

Custom UIColor+Extension

import UIKit


// creating a color object
extension UIColor {
    static let foodBulbGreen = UIColor(r: 47, g: 212, b: 128, a: 1)
    static let foodBulbOrange = UIColor(r: 255, g: 130, b: 98, a: 1)
}

// usage: UIColor.foodBulbGreen

//  convert an existing color into a hex

extension UIColor {
    var toHexString: String {
        var r: CGFloat = 0
        var g: CGFloat = 0
        var b: CGFloat = 0
        var a: CGFloat = 0
        
        self.getRed(&r, green: &g, blue: &b, alpha: &a)
        
        return String(
            format: "%02X%02X%02X",
            Int(r * 0xff),
            Int(g * 0xff),
            Int(b * 0xff)
        )
    }
}

// convert an existing hex string into a UIColor object

extension UIColor {
    convenience init(hex: String) {
        let scanner = Scanner(string: hex)
        scanner.scanLocation = 0
        
        var rgbValue: UInt64 = 0
        
        scanner.scanHexInt64(&rgbValue)
        
        let r = (rgbValue & 0xff0000) >> 16
        let g = (rgbValue & 0xff00) >> 8
        let b = rgbValue & 0xff
        
        self.init(
            red: CGFloat(r) / 0xff,
            green: CGFloat(g) / 0xff,
            blue: CGFloat(b) / 0xff, alpha: 1
        )
    }
}

// usage: UIColor(hex: "89CFF0")