If it visually appears as a list, it must be marked up as a list. Why? Screen readers will read that it's a list with the number of items within that list. Some will read when the list start and when the list ends. It's best if navigation and menus are within <ul>s.
<h3>Colors</h3>
<p>blue<br />
red<br />
green<br />
pink<br />
purple<br />
black<br />
white<br />
</p>blue
red
green
pink
purple
black
white
<h3>Colors</h3>
<ul>
<li>blue</li>
<li>red</li>
<li>green</li>
<li>pink</li>
<li>purple</li>
<li>black</li>
<li>white</li>
</ul>