Write a function that takes in two peices of text and then compares them for differences, highlighting the changes parts in green color.

var str1 = "This is string one";
var str2 = "This is string two";

function colorDiff(str1, str2){
  var i = 0;
  var resultString = "";

  while (i < str1.length || i < str2.length) {
    if (str1[i] !== str2[i]){
      resultString += "<span style='color:green'>" + str2[i] + "</span>";
    } else {
      resultString += str2[i];
    }
    i++;
  }
  return resultString;
}

colorDiff(str1, str2);