how to add color button to swift drawing app - swift

Question

EDIT: I added var out of class and than changed it by button in UIview.
in my class canvas:
`lineColor = color`
out of my class, but in canvas file
color = UIColor.black
in viewcontroller
#IBAction func blue(_ sender: Any) {
color = UIColor.blue
}
I'm creating a swift drawing app. I made special view for drawing(canvas) and now I created a button to change color, but it is not communicating with my canvas class in another file. I tried to add func to canvas and than call it by button, but it didn't work. Can someone help me please?
Here is my canvas.swift file
func blue(){
}
class Canvas: UIView {
var lineColor:UIColor!
var lineWidth:CGFloat!
var path:UIBezierPath!
var touchPoint:CGPoint!
var startingPoint:CGPoint!
override func layoutSubviews() {
self.clipsToBounds = true
self.isMultipleTouchEnabled = false
lineColor = UIColor.black
func blue(){
lineColor = UIColor.blue
}
lineWidth = 7
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first
startingPoint = touch?.location(in: self)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first
touchPoint = touch?.location(in: self)
path = UIBezierPath()
path.move(to: startingPoint)
path.addLine(to: touchPoint)
startingPoint = touchPoint
drawShapeLayer()
}
func drawShapeLayer(){
let shapeLayer = CAShapeLayer()
shapeLayer.path = path.cgPath
shapeLayer.strokeColor = lineColor.cgColor
shapeLayer.lineWidth = lineWidth
shapeLayer.fillColor = UIColor.clear.cgColor
self.layer.addSublayer(shapeLayer)
self.setNeedsDisplay()
}
func clearCanvas(){
path.removeAllPoints()
self.layer.sublayers = nil
self.setNeedsDisplay()
}

Answer 1

You can pass this color by NSUserDefault.
To save :
UserDefaults.standard.set(color, forKey: "colorKey")
To receive :
UserDefaults.standard.object(forKey: "colorKey")