autoship_edit_scheduled_order_action_button_skin

(src > scheduled-orders.php) Allows you to add/change the classes assigned to the buttons in order to change the look and feel of the ui.

Example

// Customize action button skin and span
function xx_change_action_button_skin($action_button_attr){
    $action_button_attr['action_btn'] .= ' gray';
    $action_button_attr['action_span'] .= ' notice-red';
    return $action_button_attr;
}
add_filter('autoship_edit_scheduled_order_action_button_skin', 'xx_change_action_button_skin', 10, 1);