JSFiddle - React, Tailwind, and code Playground

HTML

<select id="choice">
    <option value="0" selected="selected">Choose...</option>
    <option value="1">Something</option>
    <option value="2">Something else</option>
    <option value="3">Another choice</option>
</select>

CSS

#choice option { color: black; }
.empty { color: gray; }

JavaScript

function colorizeSelect(){
    if($(this).val() == "0") $(this).addClass("empty");
    else $(this).removeClass("empty")
}

$("#choice")
    .on('change keyup', colorizeSelect)
    .change();