JSFiddle - React, Tailwind, and code Playground

HTML

<div class="navigation red">adsa</div>

CSS

.navigation {
    height:800px;
}
.navigation.red {
    background:red;
}
.navigation.blue {
    background:blue;
}

JavaScript

$(window).scroll(function () {
    var windowY = 100;
    var scrolledY = $(window).scrollTop();
 
        console.log(scrolledY + " - " +windowY);
    if (scrolledY > windowY) {
        
        $('.navigation').addClass;
    } 
    else {
        $('.navigation').removeClass("blue");
        $('.navigation').addClass("red");
    }

});