Edit in JSFiddle

li:not(.three){
    color: blue;
}

<ul>
<li>Client-side form validation is an important part of </li>
<li>great user experience. AngularJS lets you declare the </li>
<li class="three">validation rules of the form without </li>
<li>having to write JavaScript code. </li>
<li>Write less code, go have beer sooner.</li>
</ul>