If you’re using a child theme, you could add something like this to your functions file. I do this sometimes (along with others) if I’m troubleshooting a problem.
function my_remove_filter() {
remove_filter( 'wp_head', 'graphene_webfont_script' );
remove_filter( 'admin_head-appearance_page_custom-header', 'graphene_webfont_script' );
}
add_action( 'init', 'my_remove_filter' );
Also, if anyone sees a problem with this, please don’t hesitate to correct me. PHP hurts my head and I’m just learning as I go.