JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<div>
Step 1> click on toggle button <br />

step 2> click on disable button <br />

result > Blue color of switch should change to gray when it get disabled.
 
</div>
<div>



<label class="toggleswitch" style="hidden: true" id="lblToggle">
  <input id="enableSN" name="enableSN" class="switch-input" type="checkbox" [(ngModel)]="appEnabled" (ngModelChange)="switchChange($event)">

  <div class="slider"></div>
</label>

<div>
  <button class="btn btn-primary" id="btnDisabled" text="disable" onclick="ondisabledclick()"> disable</button>
</div>
<div id="demo">
  Sample
</div>

</div>

CSS

/* The switch - the box around the slider */

.toggleswitch {
  position: relative;
  display: inline-block;
  width: 60px;
  height: 34px;
}


/* Hide default HTML checkbox */

.toggleswitch input {
  display: none;
}


/* The slider */

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  -webkit-transition: .4s;
  transition: .4s;
}

.slider:before {
  position: absolute;
  content: "\f00d";
  color: white;
  font-family: FontAwesome;
  height: 26px;
  width: 26px;
  left: 30px;
  bottom: 4px;
  background-color: #68737a;
  -webkit-transition: .4s;
  transition: .4s;
  font-size: 1.33333333em;
  vertical-align: -15%;
  text-align: center;
  font-weight: 100;
}

.toggleswitch .disabled:before {
  background-color: #d1d2d4;
}


input:checked + .slider {
  background-color: #d1d2d4;
}

input:checked + .slider:before {
  position: absolute;
  content: "\f00c";
  color: white;
  font-family: FontAwesome;
  height: 26px;
  width: 26px;
  left: -22px;
  bottom: 4px;
  background-color: #24b3e7;
  -webkit-transition: .4s;
  transition: .4s;
  font-size: 1.33333333em;
  vertical-align: -15%;
  text-align: center;
  font-weight: 100;
}



input:focus + .slider {
  box-shadow: 0 0 1px #d1d2d4;
}

input:checked + .slider:before {
  -webkit-transform: translateX(26px);
  -ms-transform: translateX(26px);
  transform: translateX(26px);
}

div .disabled {
    pointer-events: none;
    opacity: 0.5;
    background: #CCC;
  }
  
  .disabled .slider:before{
    background-color: red;
  }
.disabled input:checked + .slider:before{
  background-color: green;
}

JavaScript

function ondisabledclick() {
   var element=  document.getElementById("lblToggle");
   toggleClass(element,"disabled");
    
 }


function toggleClass(element, className){
    if (!element || !className){
        return;
    }

    var classString = element.className, nameIndex = classString.indexOf(className);
    if (nameIndex == -1) {
        classString += ' ' + className;
    }
    else {
        classString = classString.substr(0, nameIndex) + classString.substr(nameIndex+className.length);
    }
    element.className = classString;
}