在 Swift 中比较 UIColors 时出现问题

我需要比较两个 UIColor，但由于某种原因它总是返回 false。我尝试比较使用== and .isEqual()，但它们似乎都不起作用。

//This is a sample of the colors I have created
let blue_color = UIColor(red: 122/255, green: 180/255, blue: 190/255, alpha: 1)


//This is the SpriteNode I have to compare

let square = SKSpriteNode(color: randomColorController(), size: ksquaresize)

randomColorController() 只是一个随机化颜色并返回它的函数，因此在创建 square 时会调用它。

func randomColorController() -> UIColor {
    let random = arc4random_uniform(3) + 1

    switch random {
    case 1:
        let color = blue_color
        return color
    case 2:
        let color = yellow_color
        return color
    case 3:
        let color = yellow_color
        return color
    default:
        let color = UIColor.clearColor()
        return color
    }

然后，根据我创建的正方形的位置，它将检查碰撞，比较我创建的正方形的颜色和我在开始时初始化的颜色。

func checkCollision(currentTime: CFTimeInterval, Square: SKSpriteNode) -> Int{
    let color = Square.color

    print(color.isEqual(blue_color))
    print(color.isEqual(red_color))
    print(color.isEqual(yellow_color))

    if Square.position.y >= 0 && Square.position.y <= 40 {
        if color.isEqual(blue_color) && (Square.position.x < basesize.width) {
                // ADDS 1 POINT TO THE SCORE LABEL
                flag = 1
                points += 1
            } else if color.isEqual(red_color) && (Square.position.x > (basesize.width*2)){
                flag = 1
                points += 1
            } else if color.isEqual(yellow_color) && (Square.position.x < (basesize.width*2)) &&  (Square.position.x > basesize.width) {
                flag = 1
                points += 1
            } else {
                flag = -1
            }
    }

But color.isEqual(blue_color)或任何其他颜色，似乎不起作用。我已经打印了Square.color and blue_color（以及其他），并且它们匹配。但它总会回来false.

extension UIColor {
    func isEqual(color: UIColor?) -> Bool {
        guard let color = color else { return false }

        var red:CGFloat   = 0
        var green:CGFloat = 0
        var blue:CGFloat  = 0
        var alpha:CGFloat = 0
        self.getRed(&red, green: &green, blue: &blue, alpha: &alpha)

        var targetRed:CGFloat   = 0
        var targetGreen:CGFloat = 0
        var targetBlue:CGFloat  = 0
        var targetAlpha:CGFloat = 0
        color.getRed(&targetRed, green: &targetGreen, blue: &targetBlue, alpha: &targetAlpha)

        return (Int(red*255.0) == Int(targetRed*255.0) && Int(green*255.0) == Int(targetGreen*255.0) && Int(blue*255.0) == Int(targetBlue*255.0) && alpha == targetAlpha)
    }
}

我在 swift 3、4 中测试过