CirclePops

size(1100, 1000);
background(255);
float x, y, dia;
color c1, c2;
noStroke();
for (int i = 0; i<550; i++) {
  dia = random(25, width/10);
  x = random(width-dia/2+dia/2);
  y = random(height-dia/2+dia/2);
  c1 = color(random(20, 255), random(20, 255), random(10, 255),random(200,255));
  c2 = color(random(150, 200), random(150, 255), random(200, 255), random(225,255));

  fill(c1);
  ellipse(x, y, dia, dia);
  dia *=.8;
  fill(c2);
  ellipse(x, y, dia, dia);
}