     var heightConstraint: NSLayoutConstraint!
     var keyboardHeight:CGFloat = 400
     var buttonToFinger = [UIButton: Finger]()
+    var colorScheme = ColorScheme.rainbow
     
     // MARK: Keyboard states
     var shiftKeyActive = false {

    }
    
    @IBAction func touchUpFinger(_ sender: UIButton) {
        fingersPressed.removeAll()
        shiftKeyActive = false
        updateKeyLabels()

    @IBAction func touchDownFinger(_ sender: UIButton) {
        let finger = buttonToFinger[sender]!
        fingersPressed.insert(finger)
        sender.backgroundColor = colorScheme.getDarkerColor(buttonToFinger[sender]!)
        
        // Update text field
        if let letter = LetterMapping.getLetter(fingersPressed, isUpperCase: shiftKeyActive) {
