let xSpeed = 5;

let colorr = 0;

let colorInc = true;

​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(220);

​

  let colorr = map(x, 0, width, 0, 255);

​

  fill(colorr);

  ellipse(x, 200, 30, 30);

  x += xSpeed;

​

  if (x >= width || x <= 0) {

    xSpeed *= -1;

  }

}

​