let gridSize = 5;

let cellSize;

​

function setup() {

  createCanvas(600, 600);

  colors = [

    color(230, 230, 250),  // Lavender

    color(255, 182, 193),  // Pastel Pink

    color(0),              // Black

    color(255)             // White

  ];

  cellSize = width / gridSize;

  noLoop();

}

​

function draw() {

  background(255);

  for (let i = 0; i < gridSize; i++) {

    for (let j = 0; j < gridSize; j++) {

      drawConcentricSquares(i * cellSize, j * cellSize, cellSize);

    }

  }

}

​

function drawConcentricSquares(x, y, size) {

  let numSquares = floor(random(3, 8));

  let squareSize = size;

  let colorIndex1 = floor(random(colors.length));

  let colorIndex2 = floor(random(colors.length));

  while (colorIndex2 === colorIndex1) {

    colorIndex2 = floor(random(colors.length));

  }

  for (let i = 0; i < numSquares; i++) {

    if (i % 2 === 0) {

      fill(colors[colorIndex1]);

    } else {

      fill(colors[colorIndex2]);

    }

    noStroke();

    rect(x + (size - squareSize) / 2, y + (size - squareSize) / 2, squareSize, squareSize);

    squareSize -= size / numSquares;

  }

}

​

function mousePressed() {

  redraw();

}