function setup() {

  createCanvas(windowWidth,

               windowHeight);

  background(130, 432, 123);

}



function draw() {

  noStroke();



  //adding value to red and green.

  fill(frameCount, 128 + frameCount, 621, 20);



  //adding value to the radius of the circle.

  ellipse(200, 700, frameCount);

}