void setup(){
  size(653, 646);
}
void draw(){
  background(255);

  noStroke();
  fill(#de362b);
  rect(76, 81, 326, 322);
  rect(622, 497, 45, 149);
  fill(#fad168);
  rect(0, 487, 76, 160);
  rect(402, 0, 225, 235);
  fill(#100105);
  rect(76, 414, 159, 155);
  rect(244, 570, 159, 49); 
  fill(#240ea8);
  rect(412, 497, 211, 122);

  fill(0);
  rect(12, 70, 620, 11);
  rect(65, 70, 11, 560);
  rect(402, 8, 11, 611);
  rect(622, 15, 11, 615);
  rect(12, 235, 54, 11);
  rect(402, 235, 230, 11);
  rect(12, 487, 642, 11);
  rect(65, 403, 566, 11);
  rect(233, 403, 11, 228);
 
}

Note the use of # for defining the colors. Pretty useful for Photoshop's addicted people like me ;)

Best regards