4-1A

function setup() {

  createCanvas(windowWidth, windowHeight);

  background(100);

}

var r= 0;

function draw() {

  // print(r/2);

  // background(100);

  r=frameCount*5;

  var brightnessR = r/2 +40;

  var brightnessG = frameCount/2 +40;

  var brightnessB = frameCount/2 +40 + frameCount/5;

  // fill(brightnessR ,brightnessG ,brightnessB);

  var darkR = brightnessR/2;

  var darkG = brightnessG/2;

  var darkB = brightnessB/2;

  fill(darkR ,darkG ,darkB,20);

  rectMode(CENTER)

  ellipse(width/2,height/3,r,r);

  ellipse(width/2,height/2,r,r);

  ellipse(width/2,height/3*2,r,r);

}