Random 2

color black = #000000;
color white = #f1f1f1;
color primary = #ff0000;

void setup() {
  background(#f1f1f1);
  size(800, 600);
  noStroke();
}

void draw() {
  if (random(1) < 0.5) {
    fill(primary);
  } else {
    fill(black);
  }
  
  ellipse(mouseX,mouseY, 40, 40);
 
}