根据您滚动页面的距离来更改div

window.addEventListener('scroll', function() {
  const div = document.querySelector('div');
  const scrollTop = window.pageYOffset || document.documentElement.scrollTop;

  if (scrollTop > 100) {
    div.style.backgroundColor = 'red';
  } else {
    div.style.backgroundColor = 'blue';
  }
});