createCanvas(400, 400);

  background(random(255), random(255), random(255))

}

​

function draw() {

r=map(mouseX, 0, width, 0, 255)

b=map(mouseY, 0, height, 255, 0)

if (mouseIsPressed) {

fill(random(255), random(255), random(255));

background(random(255), random(255), random(255))

} else {

fill(random(r), random(b), random(r+b));

background((255-r), (255-b), (255-(r+b)))

​

}

ellipse(mouseX, mouseY, (30), (30));

​

}