-webkit-text-stroke-color

/* <color> values */
-webkit-text-stroke-color: red;
-webkit-text-stroke-color: #e08ab4;
-webkit-text-stroke-color: rgb(200 100 0);

/* Global values */
-webkit-text-stroke-color: inherit;
-webkit-text-stroke-color: initial;
-webkit-text-stroke-color: revert;
-webkit-text-stroke-color: revert-layer;
-webkit-text-stroke-color: unset;

<p>Text with stroke</p>
<input type="color" value="#ff0000" />

p {
  margin: 0;
  font-size: 4em;
  -webkit-text-stroke-width: 3px;
  -webkit-text-stroke-color: #ff0000; /* Can be changed in the live sample */
}

const colorPicker = document.querySelector("input");
colorPicker.addEventListener("change", (evt) => {
  document.querySelector("p").style.webkitTextStrokeColor = evt.target.value;
});