Draw It

function setup() {

  createCanvas(500,400);

  background(100, 100, 100);

}

function draw() {

 if (mouseIsPressed) {

    background(10, 100, 100);

  }

  stroke(50, 50, 50);

  fill(200, 200, 200);

  ellipse(mouseX, mouseY, 100, 100);

}