gistfile1.java

int ws = 640;
int st = 20;

int ed = 1;
int sd = 10;

void setup() {
  size (ws, ws);
  noStroke();
}

void draw() {
}

void keyPressed() {
  for (int i = 0; i < ws; i += st)
    for (int j = 0; j < ws; j += st) {
      float c = random(100);
      
      if (c < ed)
        fill (random(10, 50), random(10, 50), random(10, 50));
      else if (c < sd)
        fill (random(50, 100), random(50, 100), random(50, 100));
      else
        fill (random(100, 255), random(100, 255), random(100, 255));
      
      rect(i, j, i + st, j + st);
    }
   
   saveFrame("avatar-####.png");
}