JSFiddle - React, Tailwind, and code Playground

HTML

<span id="my_text">OldWord</span>

JavaScript

var lastWordTyped = "NewWord";
var ele = document.querySelector("#my_text");

lastWordTyped = capitalizeFirstLetterOfKeyword(lastWordTyped);
lastWordTyped = lastWordTyped.fontcolor("blue");
ele.innerHTML = lastWordTyped;

function capitalizeFirstLetterOfKeyword(keyword) {
        var word;
        word = keyword.charAt(0).toUpperCase() + keyword.slice(1);
        return word;
    }