     @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) {

        buttonToFinger[rightThumbFingerButton!] = Finger(side: .right, name: .thumb)
        
        updateKeyLabels()

        // Set up Settings Slide-in
        settingsOverlay.isHidden = true

    }
    
    @IBAction func touchUpFinger(_ sender: UIButton) {
        sender.backgroundColor = colorScheme.getDarkerColor(buttonToFinger[sender]!)
        fingersPressed.removeAll()
        shiftKeyActive = false
        updateKeyLabels()
