let row = 10;

​

function setup() {

  createCanvas(400, 400);

  frameRate(6);

}

​

function draw() {

  background(0);

​

  let gridW = width / column;

  let gridH = height / row;

​

  for (let a = 0; a < column; a++) {

    for (let b = 0; b < row; b++) {

      if ((a + b) % 2 == 0) {

        fill(random(0, 50));

      } else {

        fill(random(50, 100));

      }

      noStroke();

      rect(a * gridW, b * gridH, gridW, gridH);

      stroke(random(150,250), random(150,250), random(150,250));

      strokeWeight(random(4));

      fill(random(150), random(150), random(150));

      circle(a * gridW + 20, b * gridH + 20, random(15, gridW));

      noStroke();

      fill(random(255), random(255), random(255));

      circle(a * gridW + 20, b * gridH + 20, random(5, 15));

    }

  }

}

​