Hex colour code transition algorithm. Convert to .ino later!

transition.js

var element = $('div');
const original = "ff7f00";
const final = "333333";

var R = original.substring(0, 2);
var G = original.substring(2, 4);
var B = original.substring(4, 6);
console.log(R, G, B);
var finalR = final.substring(0, 2);
var finalG = final.substring(2, 4);
var finalB = final.substring(4, 6);

while ((R + G + B) != final) {
  if (parseInt(R, 16) < parseInt(finalR, 16)) {
    R = (parseInt(R, 16) + 1).toString(16);
  } else if (parseInt(R, 16) > parseInt(finalR, 16)) {
    R = (parseInt(R, 16) - 1).toString(16);
  }
  if (parseInt(G, 16) < parseInt(finalG, 16)) {
    G = (parseInt(G, 16) + 1).toString(16);
  } else if (parseInt(G, 16) > parseInt(finalG, 16)) {
    G = (parseInt(G, 16) - 1).toString(16);
  }
  if (parseInt(B, 16) < parseInt(finalB, 16)) {
    B = (parseInt(B, 16) + 1).toString(16);
  } else if (parseInt(B, 16) > parseInt(finalB, 16)) {
    B = (parseInt(B, 16) - 1).toString(16);
  }
  var current = '#' + R + G + B;
  // console.log("Setting color to", current);
  element[0].style.backgroundColor = current;
  sleep(10)
  while (element[0].style.backgroundColor != current);
  console.log("Colour changed");
  // console.log("Final:", final);
}
alert("Done");