Lighten
Use this suite of background-color utilities to directly style elements.
<div style='background-color: #555'>
<div class="center p1 bg-lighten-1">.bg-lighten-1</div>
<div class="center p1 bg-lighten-2">.bg-lighten-2</div>
<div class="center p1 bg-lighten-3">.bg-lighten-3</div>
<div class="center p1 bg-lighten-4">.bg-lighten-4</div>
</div>