JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.8.2/umd/popper.js"></script>
<link rel="stylesheet" href="ttps://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.6-rc.0/css/select2.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.6-rc.0/js/select2.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2-bootstrap-theme/0.1.0-beta.10/select2-bootstrap.min.css">
<body>
  <select multiple="multiple" id="myList" style="width:200px">
    <option value="1">Apple</option>
    <option value="2">Mango</option>
    <option value="3">Orange</option>
  </select>
</body>

JavaScript

$(document).ready(function() {

  var checkList = [1, 3];
  $("#myList").select2().val(checkList).trigger("change");
  console.log(document.getElementById("myList"));
	var colors = ["red", "blue", "green", "cyan", "orange", "aliceblue", "purple"];	//random colors that i created
	
	var selections = $(".select2-selection__choice");
	//this above will return all selections

if (selections.length){
	for (var i = 0; i < selections.length; i++){
		var selection = selections[i];
		var selectionJQ = $(selection);
		var select2ID = selectionJQ[0].dataset.select2Id;	//here you can get some infos from select2	
		colorName	= colors[select2ID];

		selectionJQ.attr("style", "background: " + colorName + " !important");
	}
}
	
})