createCanvas(400, 400);

}

​

​

​

function draw() {

var red = map(mouseX,0,400,255,0);

  var red2 = map(mouseY,0,400,0,255);

  var green = map(mouseY,0,400,0,255);

  var blue = map(mouseX,0,400,0,255);

  var blue2 = map(mouseY,0,400,0,255);

  background(red-red2,green,blue-blue2);

}