如何在每次产生时随机改变SKShapeNode的颜色？

import SpriteKit

// 创建一个自定义的SKShapeNode子类
class RandomColorShapeNode: SKShapeNode {
    override init() {
        super.init()
        
        // 设置形状和大小
        let path = CGMutablePath()
        path.addRect(CGRect(x: -50, y: -50, width: 100, height: 100))
        self.path = path
        
        // 初始时随机设置颜色
        randomizeColor()
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // 随机改变颜色
    func randomizeColor() {
        let randomRed = CGFloat.random(in: 0...1)
        let randomGreen = CGFloat.random(in: 0...1)
        let randomBlue = CGFloat.random(in: 0...1)
        let randomColor = UIColor(red: randomRed, green: randomGreen, blue: randomBlue, alpha: 1.0)
        self.fillColor = randomColor
    }
}

// 在产生SKShapeNode时，调用randomizeColor()方法即可实现随机改变颜色
let shapeNode = RandomColorShapeNode()
shapeNode.randomizeColor()