_root color set AS + PHP

Hi,
I`m trying to change the text color when getting echo text from php:

Have defined in MC a dynamic field: EmailStatus

“Submit” back command from php:


        lv.onLoad = function() {
            _root.pages.Mail.EmailStatus = this.msg;
        };


and echo from PHP


echo "&msg=Your mail was sent";

How can I make “Your mail was sent” another color instead of already choosed color for that field?