JSFiddle - React, Tailwind, and code Playground

HTML

<select class="multiselect-right" size=4>
<option style="background: #F00";>1</option>
<option>2</option>
<option>3</option>
</select>
<select class="multiselect-right" size=4>
  <option>A</option>
  <option>B</option>
  <option>C</option>
</select>

CSS

option{
  background: #F00;
}