JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><div>Item 1</div>
        <ul>
            <li><div>Item 1-1</div></li>
            <li><div>Item 1-2</div>
                <ul>
                    <li><div>Item 1-2-1</div></li>
                    <li><div>Item 1-2-2</div></li>
                </ul>
            </li>
            <li><div>Item 1-3</div></li>
        </ul>
    </li>
    <li><div>Item 2</div>
        <ul>
            <li><div>Item 2-1</div>
                <ul>
                    <li><div>Item 2-1-1</div></li>
                </ul>
            </li>
        </ul>    
    </li>
    <li><div>Item 3</div></li>
    <li><div>Item 4</div></li>
</ul>

JavaScript

$( document ).ready(function() {
    var b = true;
        
    $( "div" ).each(function( index ) {
        b = !b;
        if (b) {
            $(this).css("background-color", "#ff0000");
        } else {
            $(this).css("background-color", "#00ff00");
        }
        
    });
    
    
});