JSFiddle - React, Tailwind, and code Playground

HTML

<div class="password">
    <div class="form-group col-md-3 col-sm-4 col-xs-12">
        <label for="old" class="input">Старый пароль</label>
        <input type="text" class="form-control inputs empty" id="old" />
    </div>
    <div class="form-group col-md-3 col-sm-4 col-xs-12">
        <label for="new" class="input">Новый пароль</label>
        <input type="text" class="form-control inputs empty" id="new" />
    </div>
    <div class="form-group col-md-3 col-sm-4 col-xs-12">
        <label for="apply" class="input">Подтверждение пароля</label>
        <input type="text" class="form-control inputs empty" id="apply" />
    </div>
    <div class="clearfix"></div> <a href="" class="save empty" style="display:none;">Сохранить изменения</a>

</div>

CSS

.save.empty {
    background: red;
}
.save {
    background: green;
}

JavaScript

$(".password").on(
    'blur',
    'input',
    function () {
        $(this).toggleClass('empty', !$(this).val().length);
        $('.password').find('.save').toggle(!$(".password input.empty").length);
    }
);