let y = [30, 90, 60, 120, 180, 150];

let r = [50, 10, 100, 30, 200, 80];

let rc= [0,0,0,0,0,0];               // running radius/transparency factor

​

function setup() {

  createCanvas(300, 300);

  frameRate(5);

}

​

function draw() {

  background(200,200,0);

  //translate(width / 2, height / 2);

  draw_circles();

}

​

function draw_circles() {

  for (let i = 0; i < 6; i++) {

    stroke(255, 0, 0);

    fill(0, 200, 20, 200-rc[i]);     // when bigger more transparent

    ellipse(x[i], y[i], rc[i])

    rc[i]--;

    if (rc[i] <= 1)  rc[i] = r[i];  // looks like random cycle, but it is shuffling?

  } 

}

​