let color = 0;

let xspeed = 2;

let colorValue = 1;

​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(220);

​

  fill(color);

  ellipse(x, 200, 50, 50);

​

  //moves to the right by xspeed pixel

  x += xspeed;  

​

  //conditional if larger than 400, xspeed change direction

  if (x > width) {

    xspeed = xspeed * -1;

​

    //conditional if x is less than zero, xpeed gains direction

  } else if (x < 0) {

    xspeed = xspeed * -1;

  }

  //increase y value by yspeed

  color += colorValue;

​

​

  //if y value hits limit at 255, reduce number

  if (color > 255) {

    colorValue = colorValue * -1;

  //if y value less than 0, increase number

  } else if (color < 0) {

    colorValue = colorValue * -1;

  }

}

​