But have the top of the button "ADD TO CART" still in the blue color.

Where can I change that
.adminform button,
#adminForm button,
.button,
a.readon,
input[type="submit"],
input[type="button"],
a.button_details,
a.continue_link,
a.checkout_link {background: #436284 url('../images/style2/button.png') repeat-x 0 100%;}