Your Return Value must be set to Both (Array). That way your field will be an array that contains both the value and the name for each choice, which is what you’re looking for.
Once you have that, try this code out as an example:
$colors = get_field('features');
if( $colors ): ?>
<?php foreach( $colors as $color ): ?>
<li class="<?php echo $color['value']; ?>"><?php echo $color['label']; ?></li>
<?php endforeach; ?>
<?php endif; ?>