SOURCE

let color=[];
let d=[];
function setup(){
    createCanvas(600,600);
    rectMode(CENTER);
    background(230);
    noStroke();
    for(let i=0;i<12;i++){
        color[i]=random(255);
        }
        for(let i=0;i<3;i++){
            d[i]=random(100,200);
            }
            for(let i=0;i<3;i++){
                let index=i*3;
                fill(color[index],color[index+1],color[index+2]);
                ellipse(random(width),random(height),d[i],d[i]);
                }
}
function draw(){
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>