Hi,
1)That seems some conflict caused by a plugin. Try to disable them all except Woocommerce, clear the cache and try again.
2) Add the code below to your custom css. Adjust the color to your needs.
#breadcrumbs {
background: #ffffff!important;
}
3)Add the code below to your custom css. Adjust the color and font family to your needs.
.woocommerce form.cart button.single_add_to_cart_button, .woocommerce p.cart a.single_add_to_cart_button, ul.products li.product a.quick-view-button, .woocommerce div.product form.cart .button.add_to_cart_button {
background: #F2F2F2!important;
font-family: Arial!important;
}
-Rui