I want to select the first li without class="test" using :not and :first-child pseudoclasses. In this example I try to set color blue to <li>Third</li>:
ul li {
color:red;
}
ul li:not(.test):first-child {
color:blue;
}
<ul>
<li class="test">First</li>
<li class="test">Second</li>
<li>Third</li>
<li>Fourth</li>
</ul>