ToggleGroup group = new ToggleGroup();
final RadioButton standardGreen = new RadioButton("Green");
standardGreen.setToggleGroup(group);
standardGreen.setSelected(true);
standardGreen.setOnAction(event -> FRONT_PANEL.setBackground(new Background(new BackgroundFill(Color.GREEN, CornerRadii.EMPTY, Insets.EMPTY))));
final RadioButton amber = new RadioButton("Red");
amber.setToggleGroup(group);
amber.setOnAction(event -> FRONT_PANEL.setBackground(new Background(new BackgroundFill(Color.RED, CornerRadii.EMPTY, Insets.EMPTY))));
final RadioButton blueDarkBlue = new RadioButton("Blue");
blueDarkBlue.setToggleGroup(group);
blueDarkBlue.setOnAction(event -> FRONT_PANEL.setBackground(new Background(new BackgroundFill(Color.BLUE, CornerRadii.EMPTY, Insets.EMPTY))));
VBox componentsBack = new VBox(backButton, standardGreen, amber, blueDarkBlue);
componentsBack.setSpacing(10);
StackPane back = new StackPane();