if mysql turns red just means that mysql REFUSE to start
possible reasons ( and basicly ONLY reason)
mysql is already running on the same port
be sure to check if mysql is not running as a service , if it is then shut it down (use google to search how)
be sure to check if your other programs are not installing mysql ( xamp , wamp , easy apache and so on)
as there can be only 1 mysql running at the same time
if that fails ( in rare cases and after manual editing stuff in the mysql directory ) then you just got corrupt files and need a fresh install of mysql
there is no other solution , as the green light just checks if mysql is running from the directly that you like to start it
hope this will help you..some advise from me if you really want to learn how to solve the problems my suggestion is try read all this thread eo section then bookmark that give benefit to u seriously it will help you alot in future