I have a Wordpress CMS website where most labels are needed to be white. So the theme includes the below styles per form labels.
.login label { color: #fff;
It's not best practice to edit any wp core files, so I'd advice not to touch wp-login.php anyway, since updating WordPress can reset things.
Instead, add this to your functions.php:
// Custom login function custom_login() { $files = ''; echo $files; } add_action('login_head', 'custom_login');