JSFiddle - React, Tailwind, and code Playground

HTML

<select multiple style="background-color:red;">
    <option id="testopt">option1</option>
    <option class="option2">option2</option>
    <option class="option3">option3</option>
    <option class="option4">option4</option>
    <option class="option5">option5</option>
</select>

CSS

.option2{
    
    color:#bbbbbb;
}
.option3{
    background: #fc0; /* Цвет фона */
    color:#ff0000;
}
.option4{
    background: #f0f0f0; /* Цвет фона */
    color:#00ff00;
}
.option5{
    background: #fff; /* Цвет фона */
    color:#0000ff;
}