Order list page – conditional row background colour

In WooCommerce admin order list I want to change row background colour if order has specific shipment method. So far I’ve got:

add_action('admin_head', 'styling_admin_order_list' );

function styling_admin_order_list() {

    global $pagenow, $post;

    if( $pagenow != 'edit.php') return; // Exit
    if( get_post_type($post->ID) != 'shop_order' ) return; // Exit

    // HERE I try to check order's shipping method
    $order_shipping_method = 'Royal Mail 24'; 

    <style>
        .status-wc-processing {
            background: #d7f8a7;
            color: #0c942b;
        }
    </style>
    <?php
}

Unfortunately it colours every second row, not only row order which meets shipment method condition. Any help would be most appreciated.