::marker

li::marker {
  content: "✝ ";
  font-size: 1.2em;
}

<p>Group known as Mercury Seven:</p>
<ul>
  <li>Malcolm Scott Carpenter</li>
  <li>Leroy Gordon (Gordo) Cooper Jr.</li>
  <li>John Herschel Glenn Jr.</li>
  <li>Virgil Ivan (Gus) Grissom</li>
  <li>Walter Marty (Wally) Schirra Jr.</li>
  <li>Alan Bartlett Shepard Jr.</li>
  <li>Donald Kent (Deke) Slayton</li>
</ul>

::marker {
  /* ... */
}

<ul>
  <li>Peaches</li>
  <li>Apples</li>
  <li>Plums</li>
</ul>

ul li::marker {
  color: red;
  font-size: 1.5em;
}