Don't think there's a similar answer here so try this. Assuming HTML of:
<ul>
<li>before</li>
<li class="target">target</li>
<li>after</li>
<li>after</li>
</ul>
Add a style to all the children, then undo the style to the target, and sibling children of your target.
ul > li { color: red; }
ul > li.target, ul > li.target ~ li { color: inherit; }