function setup() {

  createCanvas(400, 400);

  frameRate(1);

  noFill();

  strokeWeight(1);

}

​

function draw() {

  let x = 0;

  let y = 0;

  let r = 0;

  let c_red = 255;

  let c_green = 255;

  let c_blue = 105;

  background('black');

  for (let i=0; i<40; i++){

    c_red = c_red-6;

    c_green = c_green-2;

    c_blue = c_blue+2;

    stroke(c_red, c_green, c_blue);

    y = 0.5*i*i;

    rad = y;

    ellipse(x+200,y,rad,rad);

  }

}