Green

void setup() {
  size(640, 480);
};

void draw () {

  background(60, 100, 55);

int MainFaceX = width/2;
int MainFaceY = height/2;
int FaceSize = 300;

  //mainhead
  fill(255);
  ellipse(MainFaceX, MainFaceY, FaceSize, FaceSize);

  //lefteyeball
  fill(255);
  ellipse(FaceSize-50, MainFaceY-40, FaceSize-200, FaceSize-200);

  //right eyeball
  fill(255);
  ellipse(MainFaceX+80, MainFaceY-40, FaceSize-200, FaceSize-200);

  //mouth
  noFill();
  arc(350, 300, 50, 50, 0, HALF_PI);

  //pupil right
  fill(0);
  ellipse(MainFaceX-70, MainFaceY-40, FaceSize-250, FaceSize-250);

  //pupil left
  fill(0);
  ellipse(MainFaceX+80, MainFaceY-40, FaceSize-250, FaceSize-250);
};

Spend a lot of time to remember which part is what variable, what it affects and how to do properly the line and coordination of everything.

the version I liked the best

#when you have to look discreetly at someone

confusing code:

• deletes the line, eyeballs and mouth

smooth();
noStroke();
fill(255,0,0);
beginShape();
vertex(50, 15);
bezierVertex(50, -5, 90, 5, 50, 40);
vertex(50, 15);
bezierVertex(50, -5, 10, 5, 50, 40);
endShape();

https://www.processing.org/discourse/beta/num_1246205739.html - credit