function setup() {

  createCanvas(windowWidth,

               windowHeight);

  background(234, 234, 234);

}



function draw() {

  var from = color(0, 20, 25, 40);

  var to = color(255, 0, 0, 100);



  fill(lerpColor(from, to, random(1.1)));

  circle(random(width), random(height), 250, 250);

}