Earlier we posted an article which will allow you to set a default admin color scheme in WordPress for new users. That snippet doesn’t change the color scheme for old users and will also not stop them from choosing another admin color scheme from their profile section.
Now, this snippet will prevent users from changing admin color scheme in WordPress. Just add following snippet to your current theme’s functions.php file:
if ( !current_user_can('manage_options') )
remove_action( 'admin_color_scheme_picker', 'admin_color_scheme_picker' );
Above code will remove the color scheme picker from the profile screen of all users except users with administrator privileges. Now, you may wanna set a default admin color scheme for your website, which you can learn on this article.