ADDITIONAL SYSTEM INFORMATION :
Windows 10, java version 15.0.1, JavaFX version 16-ea+6

A DESCRIPTION OF THE PROBLEM :
The 'Use' and 'Save' options(on custom colors window) minimize the stage instead of only closing the custom colors window, this doesn't always happen but very often instead.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1) Start the application
2) Click the 'Custom Color' window on the color picker and click either 'Use' or 'Save'

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Only the custom colors window should have closed
ACTUAL -
the stage/window minimized

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.ColorPicker;
import javafx.scene.control.Label;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class HelloWorld extends Application {

    @Override
    public void start(Stage primaryStage) {
        BorderPane root = new BorderPane();

        root.setCenter(new ColorPicker(Color.TOMATO));

        primaryStage.setScene(new Scene(root));
        primaryStage.sizeToScene();
        primaryStage.centerOnScreen();
        primaryStage.show();

        Stage second = new Stage();
        second.setScene(new Scene(
                new AnchorPane(new Label("Hello world"))
        ));
        second.show();
    }

    public static void main(String[] args) {
        Application.launch(args);
    }

}
---------- END SOURCE ----------

FREQUENCY : often