If you use bootstrap and you need to change checkbox background color, just override these styles:
.custom-checkbox .custom-control-input:checked ~ .custom-control-label::before {
background-color: green!important;
}
.custom-checkbox .custom-control-input:checked:focus ~ .custom-control-label::before {
box-shadow: 0 0 0 1px #fff, 0 0 0 0.2rem rgba(0, 255, 0, 0.25)
}
.custom-checkbox .custom-control-input:focus ~ .custom-control-label::before {
box-shadow: 0 0 0 1px #fff, 0 0 0 0.2rem rgba(0, 0, 0, 0.25)
}
.custom-checkbox .custom-control-input:active ~ .custom-control-label::before {
background-color: #C8FFC8;
}
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
<div class="myTest custom-control custom-checkbox">
<input type="checkbox" class="custom-control-input" id="customCheck1" />
<label class="custom-control-label" for="customCheck1">Check this custom checkbox</label>
</div>