Change color of external viewcontroller (swift) : I have a view controller and a container view in it. Unfortunately however, I am unable to change the color of the child view controller represented in the container view from the parent class. Changing the background color of the container view, which is the only thing I am able to reach from my parent view controller, does not change the background color of the referenced child, but only the invisible container view holding it. 

Therefore, I have tested a method where I call a function from within the class of the child from the parent as shown below:

    @IBAction func changeToRed(sender: viewController) {
        self.view.backgroundColor = UIColor(red: 230/255, green: 80/255, blue: 30/255, alpha: 1.0)
    }

(This is in the child view controller)

    otherView().changeToRed(sender: self)
(This in the parent view controller)

This technique does not work. I have already tried it with a regular function and with random trial and error in the parent view controller. Is there anything obvious I am doing wrong? Or is there a potentially a different technique to do this? Thank you in advance!
