Homework - BreakOut the game

import java.awt.Color;
import acm.program.*; 
import acm.graphics.*;

public class BreakOut extends GraphicsProgram
{
public static final int APP_WIDTH = 400;
public static final int APP_HEIGHT = 600;

private static final int PADDLE_Y_OFFSET = 30;
private static final int PADDLE_WIDTH = 60;
private static final int PADDLE_HEIGHT = 10;
private static final int PADDLE_STARTX = (APP_WIDTH / 2) - (PADDLE_WIDTH / 2);
private static final int PADDLE_STARTY =  APP_HEIGHT - PADDLE_Y_OFFSET;

private static final int BRICK_Y_OFFSET = 70;
private static final int BRICK_ROWS = 10;
private static final int BRICK_COLUMNS = 10;
private static final int BRICK_SEPARATION = 4;
private static final int BRICK_HEIGHT = 8;
private static final int BRICK_WIDTH = (APP_WIDTH - (BRICK_COLUMNS - 1) * BRICK_SEPARATION) / BRICK_COLUMNS;

private static final int BALL_RADIUS = 10;
private static final int BALL_STARTX = (APP_WIDTH / 2) - (BALL_RADIUS / 2);
private static final int BALL_STARTY =  APP_HEIGHT / 2;

private GOval ball;
private GRect paddle;

public void run() 
{
    addBricks();
    addBall();
    addPaddle();
}

private void addBricks()
{
    int brickY = BRICK_Y_OFFSET;
    GRect brick;
    for (int i = 0; i < BRICK_ROWS; i++) 
    {
        int brickX = BRICK_SEPARATION;

        for (int j = 0; j < BRICK_COLUMNS; j++) 
        {
            brick = new GRect(brickX, brickY, BRICK_WIDTH, BRICK_HEIGHT);
            add(brick);

            colorBricks(brick, Color.RED, 0, 1);
            colorBricks(brick, Color.ORANGE, 2, 3);
            colorBricks(brick, Color.YELLOW, 4, 5);
            colorBricks(brick, Color.GREEN, 6, 7);
            colorBricks(brick, Color.CYAN, 8, 9);

            brickX += BRICK_WIDTH + BRICK_SEPARATION;
        }
        brickY += BRICK_HEIGHT + BRICK_SEPARATION;
    }
}

private void colorBricks(GRect brick, Color color, int firstRow, int lastRow) 
{
    if (brick.getY() >= BRICK_Y_OFFSET + firstRow * (BRICK_HEIGHT + BRICK_SEPARATION) && brick.getY() <= BRICK_Y_OFFSET + lastRow * (BRICK_HEIGHT + BRICK_SEPARATION)) 
    {
        brick.setColor(color);
        brick.setFilled(true);
    }
}

private void addBall()
{
    ball = new GOval(BALL_STARTX, BALL_STARTY, BALL_RADIUS, BALL_RADIUS);
    ball.setFilled(true);
    add(ball);
}

private void addPaddle()
{
    paddle = new GRect(PADDLE_STARTX, PADDLE_STARTY, PADDLE_WIDTH, PADDLE_HEIGHT);
    paddle.setFilled(true);
    add(paddle);
}
}