<script src="https://code.jquery.com/jquery-3.6.4.min.js"></script>

(function($) {
    $(document).ready(function() {
        var header = $('#brxe-htjiwp');//header section ID
        $(window).on('scroll', function() {
            var scroll = $(window).scrollTop();

            if (scroll > 100) { 
                header.css('background-color', 'rgba(249, 248, 247, 0.5)');//Add what color you needs to change when scroll
            } else {
                header.css('background-color', '');
            }
        });
    });
})(jQuery)