Hello,
Our theme does not have option to change WooCommerce notification styles. We can suggest you custom CSS. Please add this code to the Theme Settings > Custom CSS > Global:
body .woocommerce-message{
background-color:red;
font-size:12px;
color:white;
}
body .woocommerce-info{
background-color:red;
font-size:12px;
color:white;
}
body .wpcf7-mail-sent-ok{
background-color:red;
font-size:12px;
color:white;
}
body div.wpcf7-validation-errors{
background-color:red;
font-size:12px;
color:white;
}
body .mc4wp-success,
body .mc4wp-error{
background-color:red;
font-size:12px;
color:white;
}
Set the color and size as per your needs.
Best Regards.