import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.Background;
import javafx.scene.layout.BackgroundFill;
import javafx.scene.layout.CornerRadii;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class App extends Application {
    public static void main(String[] args) throws Exception {
        launch(args);
    }

    @Override
    public void start(Stage stage) throws Exception {
        StackPane root = new StackPane();
        Label label1 = new Label("Valami");
        label1.setTextFill(Color.AQUA);
        label1.setBackground(
            new Background(
                new BackgroundFill(Color.WHITE, CornerRadii.EMPTY, Insets.EMPTY)
            )
        );
        root.getChildren().add(label1);
        
        stage.setScene(new Scene(root, 400, 300));
        stage.show();
    }
}