Hi there psarmaputra7,

Thanks for reaching out! To achieve the mentioned effect, you could, for example, consider creating a blur event listener on <input>, that would be checking whether it has .valid /.invalid class after validation, and it so, it would be changing color properties of previously cashed elements. It could look something like that:

$(document).ready(function() {
  var icon =$('#icon');
  var input =$("#form2");
  input.blur(function(){
    if (input.hasClass('valid')) {
      icon.css('color', '#4285F4')
    } else if (input.hasClass('invalid')) {
      icon.css('color', 'red')
    }
  })
});

Hope it helps you find what you are looking for.

With Best Regards,
Kuba