SOURCE

function setup() {
    createCanvas(600, 600);
    background(500);
    noStroke();
}

function draw() {
    for (let y = 80; y < 500; y += 80) {
        for (let x = 80; x < 500; x += 80) {
        fill(random(360),200,200,20);
        ellipse(x, y, 80, 80);
    }
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>