JSFiddle - React, Tailwind, and code Playground

HTML

<p>
Some text
<a href="#foo">This is a link that should be underlined when monochrome</a> 
and some more text</p>

CSS

a {
  text-decoration: none;
}

@media (monochrome) { 
  a {
    text-decoration: underline;
  }
}