cant see to grab these CSS classes to change colour of buttons

http://freshfields.promoting-u.co.uk/freshfields-residents-kb/

Hi I am trying to change the colour of the buttons in each of these classes but i cant seem to grab them. Can you assist please?

First row (Centres)
style-centre-btns

Animals
style-animal-btns

Other Modifiers (Sex, Age, Pair etc)
style-extra-btns

View All Button
style-viewall-btn