Button not taking style from Theme

Hello – Hope you can help me with this. My site (www.heathcoteschool.co.uk) is working fine apart from the garish aqua-blue buttons you can see on the homepage. The correct colors/settings for the buttons are set in the theme (Customise -> Other Settings), see below, but seem to be overridden by something. It just appears to be the buttons affected.

Any ideas on what is causing this much appreciated!

The page I need help with: [log in to see the link]