​

function setup() {

  createCanvas(windowWidth, windowHeight);

  background(220, 20, 120);

  noLoop();

}

​

function draw() {}

​

function mouseClicked() {

  if (bgColorIndex == 0) {

    bgColorIndex = 1;

    background("gold");

  } else if (bgColorIndex == 1) {

    bgColorIndex = 2;

    background("darkgreen");

  } else if (bgColorIndex == 2) {

    bgColorIndex = 3;

    background("darkblue");

  } else if (bgColorIndex == 3) {

    bgColorIndex = 0;

    background(220, 20, 120);

  }

}

​