set div border color code example
Example 1: border color css
border: 1px solid #000000;
Example 2: javascript for border color
var getColor = prompt("Choose your color ", "Enter the color ");
var color;
var el = document.getElementById("color");
el.innerHTML = "Whatever paragraph message.";
if (getColor =="Yellow" || getColor =="yellow" || getColor =="YELLOW"){
color = "#FFFF66";
el.style.borderColor = color;
}