Color picker

The bustling city was alive with energy, as people rushed to and fro, each lost in their own thoughts and worries. The tall skyscrapers loomed over the streets, casting long shadows that stretched out towards the parks and squares below. Amidst the hubbub of the city.

This add in end of you draw block что бы курсор был виден поверх всей другой графики

push();

  //dot
  stroke(45);
  strokeWeight(4);
  point(mouseX, mouseY);  
  
  //color
  fill(0);
  textSize(20);
  color c = img.get(mouseX, mouseY);
  text("R: " + int(red(c)) + "G: " + int(green(c)) + "B: " + int(blue(c)), mouseX + 12, mouseY + 26);
      
pop();

You need add background in draw block befor you maine code что бы за курсором не сотавалось шлейфа

background(255);