change option tag css

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://stackpath.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap-select.min.css" rel="stylesheet" />
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap-select.min.js"></script>

<select class="selectpicker">
  <option>Mustard</option>
  <option class="special">Ketchup</option>
  <option style="background: #5cb85c; color: #fff;">Relish</option>
</select>

body {
    padding:50px;
    background-color:white;
}
.s-hidden {
    visibility:hidden;
    padding-right:10px;
}
.select {
    cursor:pointer;
    display:inline-block;
    position:relative;
    font:normal 11px/22px Arial, Sans-Serif;
    color:black;
    border:1px solid #ccc;
}
.styledSelect {
    position:absolute;
    top:0;
    right:0;
    bottom:0;
    left:0;
    background-color:white;
    padding:0 10px;
    font-weight:bold;
}
.styledSelect:after {
    content:"";
    width:0;
    height:0;
    border:5px solid transparent;
    border-color:black transparent transparent transparent;
    position:absolute;
    top:9px;
    right:6px;
}
.styledSelect:active, .styledSelect.active {
    background-color:#eee;
}
.options {
    display:none;
    position:absolute;
    top:100%;
    right:0;
    left:0;
    z-index:999;
    margin:0 0;
    padding:0 0;
    list-style:none;
    border:1px solid #ccc;
    background-color:white;
    -webkit-box-shadow:0 1px 2px rgba(0, 0, 0, 0.2);
    -moz-box-shadow:0 1px 2px rgba(0, 0, 0, 0.2);
    box-shadow:0 1px 2px rgba(0, 0, 0, 0.2);
}
.options li {
    padding:0 6px;
    margin:0 0;
    padding:0 10px;
}
.options li:hover {
    background-color:#39f;
    color:white;
}