Genuary15 and 17 - coming to and fading away in a grid of milliseconds

let n = 5;
let t = 0;
function setup() {
  cnv = createCanvas(500, 500);
  angleMode(DEGREES);
  noStroke();
  strokeWeight(0.2);
  c2 = color(0, 0, 0);
  c2.setAlpha(10);
  stroke(c2);
}
function draw() {
  background(c2);
  translate(width / 2, height / 2);
  t = frameCount / 30;
  drawGrid(width, true, 255);
}

function drawGrid(d, b, c) {
  for (let i = -2; i < n + 1; i++) {
    for (let j = -2; j < n + 1; j++) {
      push();
      rotate(720 * sin((-t * j * i) / 500));
      translate(100 * sin(t * i * j), 100 * sin(t * i * j));

      rotate(360 * sin(t));
      color1 = color(
        255 *
          (sin(millis() / 30 + i + j + t) * sin(millis() / 60 + j * i + 90)),
        255 *
          (sin(millis() / 40 + i + j - t) * sin(millis() / 60 + j * i + 90)),
        255 * (sin(millis() / 60 + i + j) * sin(millis() / 60 + j * i + 90))
      );
      color1.setAlpha(100);
      fill(color1);
      rect(
        -width / 2 + (d / n) * i,
        -width / 2 + (d / n) * j,
        d / n,
        d / n,
        4,
        4,
        4,
        4
      );
      if (b) {
        push();

        translate((d / n) * i, (d / n) * j);

        drawGrid(d / n, false, c);
        pop();
      }
      pop();
    }
  }
}

function mousePressed() {
  frameCount = 0;
  setup();
  draw();
}