JSFiddle - React, Tailwind, and code Playground

HTML

<style>  
.black { color:black }
.red { color: red }    
</style>
<li id="navmenu" class="black">test</li>

JavaScript

var item = dojo.byId("navmenu");
dojo.connect(item, "onmouseenter", function() {
    dojo.toggleClass(item, "red");
});
dojo.connect(item, "onmouseleave", function() {
    dojo.toggleClass(item, "red");
});