SOURCE

let c=[];
function setup(){
    createCanvas(500,500);
    noStroke
    background(220);
    for(let i=0;i<72;i++){
         c[i]=random(255);
    }
}
    function draw(){
    for(let i=0;i<24;i++){
        let index=i*3;
        fill(c[index],c[index+1],c[index+2]);
    ellipse(random(500),random(500),c[i],c[i]);
    }
}