JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test">
   <p>This should be red</p>
   <p class="abc">This should be green</p>
   <p class="newname">This should be green</p>
   <p class="">This should be red</p>
   <p class="anothername">This should be green</p>
   <p>This should be red</p>
   <p class="">This should be red</p>
</div>

CSS

body{
  font-weight:700;
}
p{background:green}

#test p:not([class]) {
  background:red;
  color:#fff;
}