Change chart colors for different values [duplicat

This question already has an answer here:

How to change color of a single bar java fx 1 answer

I want to create temperature chart where I can monitor in real time temperature.

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.StackedAreaChart;
import javafx.scene.chart.XYChart;
import javafx.stage.Stage;

public class MainApp extends Application
{

    final NumberAxis xAxis = new NumberAxis(1, 31, 1);
    final NumberAxis yAxis = new NumberAxis();
    final StackedAreaChart<Number, Number> sac
        = new StackedAreaChart<Number, Number>(xAxis, yAxis);

    @Override
    public void start(Stage stage)
    {


        setUserAgentStylesheet(STYLESHEET_CASPIAN);
        stage.setTitle("Area Chart Sample");
        sac.setTitle("Temperature Monitoring (in Degrees C)");
        XYChart.Series<Number, Number> seriesApril
            = new XYChart.Series<Number, Number>();
        seriesApril.setName("April");
        seriesApril.getData().add(new XYChart.Data(1, 4));
        seriesApril.getData().add(new XYChart.Data(3, 10));
        seriesApril.getData().add(new XYChart.Data(6, 15));
        seriesApril.getData().add(new XYChart.Data(9, 8));
        seriesApril.getData().add(new XYChart.Data(12, 5));
        seriesApril.getData().add(new XYChart.Data(15, 18));
        seriesApril.getData().add(new XYChart.Data(18, 15));
        seriesApril.getData().add(new XYChart.Data(21, 13));
        seriesApril.getData().add(new XYChart.Data(24, 19));
        seriesApril.getData().add(new XYChart.Data(27, 21));
        seriesApril.getData().add(new XYChart.Data(30, 21));
        XYChart.Series<Number, Number> seriesMay
            = new XYChart.Series<Number, Number>();
        seriesMay.setName("May");
        seriesMay.getData().add(new XYChart.Data(1, 20));
        seriesMay.getData().add(new XYChart.Data(3, 15));
        seriesMay.getData().add(new XYChart.Data(6, 13));
        seriesMay.getData().add(new XYChart.Data(9, 12));
        seriesMay.getData().add(new XYChart.Data(12, 14));
        seriesMay.getData().add(new XYChart.Data(15, 18));
        seriesMay.getData().add(new XYChart.Data(18, 25));
        seriesMay.getData().add(new XYChart.Data(21, 25));
        seriesMay.getData().add(new XYChart.Data(24, 23));
        seriesMay.getData().add(new XYChart.Data(27, 26));
        seriesMay.getData().add(new XYChart.Data(31, 26));
        Scene scene = new Scene(sac, 800, 600);
        sac.getData().addAll(seriesApril);
        stage.setScene(scene);
        stage.show();
    }

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

I want to change the color of of the chart for height temperature. For example I want to see temperature between 10 and 20 in green and temperature between 40 and 50 in red. Can you hep me to implement this?

This is only possible with CSS.
Add the following lines to your CSS and give your chart the id temperatureChart.

#temperatureChart .series0.chart-series-area-fill {
    -fx-fill: linear-gradient(to top, #0984df, #00d8ff 20%, #fff000 60%, #ff0000) ;
}

The right percent values you must figure out yourself.

Hope this helps,
Kalasch

EDIT(in code method):
To do this in Code, you can do the following(it is suggested that you check if the lookup is null):

sac.lookup("#temperatureChart .series0.chart-series-area-fill")
.setStyle("-fx-fill: linear-gradient(to top, #0984df, #00d8ff 20%, #fff000 60%, #ff0000);");

It is not recomended to do so, but if there is no other way...