createCanvas(400, 400);

  pixelDensity(1);

}

​

function draw() {

  background(50);

  loadPixels();

  for (let y = 0; y < height; y++) {

    for (let x = 0; x < width; x++) {

      let index = (x + y * width) * 4;

      pixels[index + 0] = x;

      pixels[index + 1] = random(60);

      pixels[index + 2] = y;

      pixels[index + 3] = 100;

    }

  }

  updatePixels();

}