how to change text color in javascript code example

Example 1: how to change the color using js

<!DOCTYPE html>
<html>
<head>
<script>
function display()
{
var col=document.getElementById("demo");
col.style.color="#FF0000";
}
</script>
</head>
<body>

<h1>My First JavaScript</h1>
<p id="demo">click on the button below.....</p>

<button onclick="display()">Display</button>

</body>
</html>

Example 2: js element text color

element.style.color = '#f0f';

Example 3: javascript change font color based on value

//This is in RGB since it's the one I'm most used to
function FontColor(r,g,b,textHolder){
	textHolder.style.color = "rgb("+r+","+g+","+b+")"
}

//This will make the font color of the "text" box yellow
const text = document.getElementById("TextHolder")
FontColor(255,255,0,text)