JSFiddle - React, Tailwind, and code Playground

HTML

<select>
    <option value="all_clicks"  selected="selected" class="greenRect">All clicks</option>
    <option value="search_camp">Search campaigns</option>
    <option value="search_links">Search links</option>
    <option value="none">None</option>
</select>

CSS

.greenRect{
    height:15px;
    width:15px;
    backround:#7db22b;
    border-radius:2px;
}