createCanvas(400, 400);

  colorMode(HSB)

  ball.x = random(100);

  ball.y = random(50);

}

​

let ball = {

  x: 100,

  y: 50,

  r: 50,

  xspeed: 1,

  yspeed: 1,

  col: 360,

};

​

function draw() {

  background(220);

​

  noStroke();

  fill(ball.col, 100, 100);

  circle(ball.x, ball.y, ball.r);

​

  ball.x += ball.xspeed;

  ball.y += ball.yspeed;

​

  if (ball.x + ball.r / 2 >= width || ball.x + -ball.r / 2 < 0) {

    ball.xspeed = -ball.xspeed;

    ball.col = random(150)

  }

  if(ball.y + ball.r / 2 >= height || ball.y + -ball.r / 2 < 0){

    ball.yspeed = -ball.yspeed;

    ball.col = random(150)

  }

}

​