Java swing - painted rectangles not showing up

Java swing - painted rectangles not showing up

I've been trying for quite a while to get this to work and done a lot of
research but I can't work out why it's not happening: My end goal is get a
grid of x by y green squares, and when you click on a square it changes
colour. (this is part of a bigger project)
Now I am aware that this is probably a very inefficient way of doing so,
but I've tried different ways and nothing seems to work.
In my Grid class I have this:
squares = new Square[width][height];
for (int i = 0; i < width; i++){
for (int j = 0; j < height; j++){
squares[i][j] = new Square(i,j);
frame.getContentPane().add(squares[i][j]);
}
}
And this is my Square class:
public class Square extends JLabel implements MouseListener{
private int x,y,width,height, mouseX,mouseY;
private Color colour = Color.GREEN;
public Square(int width, int height){
this.x = width*45;
this.y = height*45;
addMouseListener(this);
this.setBounds(x, y, 45, 45);
}
public void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g;
g2.setColor(colour);
g2.fillRect(x, y, 45, 45);
}
@Override
public void mouseClicked(MouseEvent e) {
mouseX = e.getX();
mouseY = e.getY();
if(mouseX > x && mouseX < x+45 && mouseY > y && mouseY < y+45){
if(colour.equals(Color.GREEN)){
colour = Color.RED;
} else{
colour = Color.GREEN;
}
repaint();
}
}
}
However when I run the code, all I see is the first square and the last
square, HOW COMES?
Also if you have any tips of how I could have done this far more
efficiently, please do tell and criticize this code.
Thank you for taking the time to read this, and a further thank you if you
care to respond <3