JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.7.5/css/bootstrap-select.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.7.5/js/bootstrap-select.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<select id="regionSelecBox" class="selectpicker" data-style="btn-danger" data-container="body"
         data-live-search="true" data-width="auto" data-size="10">
         <option class="btn-select-option" value="2200">2200 - Ontario Est</option>
         <option class="btn-select-option" value="2300">2300 - Centre Ontario/MB</option>
         <option class="btn-select-option" value="2400">2400 - Ouest</option>
         <option class="btn-select-option" value="2500">2500 - Atlantique</option>
</select>

JavaScript

//$("select").selectpicker({style:'btn-warning'});

//$("select").selectpicker({style:'btn-info'});

$("select").selectpicker('setStyle', 'btn-info', 'remove');

//$("select").selectpicker('setStyle', 'btn-warning');

$("select").selectpicker('setStyle', 'btn-success');