function setup() {

  createCanvas(600, 600);

}

​

function draw() {

  background(0);

  let  gcolor = ["#1ca152", "#008529"];

  for (a = 40; a <= 600; a = a + 15) {

     for (h = 20; h <= 600; h = h + 60) {

        for ( s = random (1,80); s <= random (1,20); s = s + 50) {

          fill(random(gcolor));

          circle(a, h, s);

        }

      }

  }

}