I understand that this is a sort of unusual request, but it's one that fits my need.
I believe I would need a query (or something) to enter in phpMyAdmin to do this. Each user on WordPress has an option in "Your Profile" page of WP-Admin (http://mydomain.com.com/wp-admin/profile.php) to change the "Admin Color Scheme" that they see. I have found that the color scheme option is saved in "wp_usermeta" table of Database with the "meta_key" of "admin_color".
So basically, I want to change everyone's color scheme to the black/gray (/boring) color scheme, which has the "meta_value" of "fresh".
I have backed up my database and entire website and I take full responsibility if anything goes wrong. It would really be appreciated if a WPMU Dev staff member could write a script to change all users' "meta_value" to "fresh"/make their color scheme gray/black-ish. Please respond as soon as possible. Thanks in advance!