JSFiddle - React, Tailwind, and code Playground

HTML

<select class="auto">
  <option value="volvo" style="background-color: red">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

CSS

.auto{
    width: 120px;
}