How to draw a custom color palette of an image

I have a GUI that downloads an image from url and after that, there is a draw button using JFileChooser that selects the downloaded image and creates color palette of that image.

@Override
        public void widgetSelected(SelectionEvent e) 
        {
            try
            {
                JFrame parentFrame = new JFrame();
                JFileChooser fileChooser = new JFileChooser();

                fileChooser.setDialogTitle(txtUrl.getText());   

                int userSelection = fileChooser.showOpenDialog(parentFrame);

                if (userSelection == JFileChooser.APPROVE_OPTION) 
                {
                    File fileToSave = fileChooser.getSelectedFile();
                    String fileName = fileToSave.getAbsolutePath();
                    BufferedImage image = null;
                    image = ImageIO.read(new File(fileName));

                    ArrayList<String> colorList = new ArrayList<String>();

                    Bitmap bitmap = new Bitmap(image);
                    Palette palette = Palette.generate(bitmap);

                    int vibrant = palette.getVibrantColor(0xFFFFFF);
                    int vibrantLight = palette.getLightVibrantColor(0xFFFFFF);
                    int vibrantDark = palette.getDarkVibrantColor(0xFFFFFF);
                    int muted = palette.getMutedColor(0xFFFFFF);
                    int mutedLight = palette.getLightMutedColor(0xFFFFFF);
                    int mutedDark = palette.getDarkMutedColor(0xFFFFFF);

                    String hexColor = String.format("#%06X", (0xFFFFFF & vibrant)); 
                    colorList.add(hexColor);

                    hexColor = String.format("#%06X", (0xFFFFFF & vibrantLight));   
                    colorList.add(hexColor);

                    hexColor = String.format("#%06X", (0xFFFFFF & vibrantDark));        
                    colorList.add(hexColor);

                    hexColor = String.format("#%06X", (0xFFFFFF & muted));  
                    colorList.add(hexColor);

                    hexColor = String.format("#%06X", (0xFFFFFF & mutedLight)); 
                    colorList.add(hexColor);

                    hexColor = String.format("#%06X", (0xFFFFFF & mutedDark));      
                    colorList.add(hexColor);

                    drawPalet(fileName, colorList);
                    System.out.println(colorList);
                    JOptionPane.showMessageDialog(null, "DRAWING IS FINISHED");
                }
            }
            catch(Exception ex)
            {
                System.out.println("CAN'T DRAW!");
                ex.getMessage();
            }
        }
    });
    btnDraw.setBounds(210, 117, 90, 30);
    btnDraw.setText("Draw");
}

public static void drawPalet(String fileName, ArrayList<String> colorList) 
{       
    BufferedImage b_img = new BufferedImage(500, 100,BufferedImage.TYPE_INT_RGB);
    Graphics2D graphics = b_img.createGraphics();
    int i=0;
    for(String color:colorList)
    {
        java.awt.Color colorAwt = new java.awt.Color(hex2Rgb(color, 0), hex2Rgb(color, 1), hex2Rgb(color, 2));

        graphics.setBackground(colorAwt);
        graphics.fillRect(i, 0, 100, 100);
        i=+100;
    }

    File outputfile = new File(fileName + "_drawed.jpg");
    try 
    {
        ImageIO.write(b_img, "jpg", outputfile);
    } 
    catch (IOException e) 
    {
        e.printStackTrace();
    }
}

public static int hex2Rgb(String colorStr, int val) 
{
    if(val == 0)
        return Integer.valueOf(colorStr.substring(1, 3), 16);
    else if (val == 1)
        return Integer.valueOf(colorStr.substring(3, 5), 16);
    else if(val == 2)
        return Integer.valueOf(colorStr.substring(5, 7), 16);
    else
        return 0;
}

The image for to use to create custom color palette:

But the codes create an image like this:

50% is white, 50% black. But it should create an image contains green and white colors. What am I doing wrong?