JSFiddle - React, Tailwind, and code Playground

HTML

<input type="radio" name="text" id="black">B<br/>
<input type="radio" name="text" id="white">W
<textarea id="text" placeholder="Explanation (Optional)"></textarea>

JavaScript

function black() {
  document.getElementById("text").style.color="#059126";
}
function white() {
  document.getElementById("text").style.color="#ffffff";
}


document.getElementById('black').addEventListener("click", black);
document.getElementById('white').addEventListener("click", white);