Now we’re getting somewhere!
What is your field type? Are they choosing via radio buttons or select?
To get the value (not the name) of your radio/select, you just do it how I explained above:
echo '<div class="' . get_field('header_bullets_and_testimonials_colour') . '">';
Just make sure your field ‘Choices’ are setup to work as classes… so it would be:
class-one | Class One
class-two | Class Two
… as seen in the first image here: http://www.advancedcustomfields.com/resources/checkbox/
