UIColor extension with hex initializers

UIColor+Ext.swift

fileprivate extension UIColor {
  convenience init(red: Int, green: Int, blue: Int) {
    assert(red >= 0 && red <= 255, "Invalid red component")
    assert(green >= 0 && green <= 255, "Invalid green component")
    assert(blue >= 0 && blue <= 255, "Invalid blue component")
    
    self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
  }
  
  convenience init(red: Int, green: Int, blue: Int, opacity: CGFloat) {
    assert(red >= 0 && red <= 255, "Invalid red component")
    assert(green >= 0 && green <= 255, "Invalid green component")
    assert(blue >= 0 && blue <= 255, "Invalid blue component")
    assert(opacity >= 0 && opacity <= 1, "Invalid alpha component")
    
    self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: opacity)
  }
  
  convenience init(hex: Int) {
    self.init(red:(hex >> 16) & 0xff, green:(hex >> 8) & 0xff, blue:hex & 0xff)
  }
  
  convenience init(hex: Int, alpha: CGFloat) {
    self.init(red:(hex >> 16) & 0xff, green:(hex >> 8) & 0xff, blue:hex & 0xff, opacity: alpha)
  }
}