re Sky HD?

We have a Bush television model LCD32TV022HD.This week we had a Sky HD+ box installed.The tv does not allow us to wacth HD as the colours are predominately green.The engineer says it's the componenent which is incorrect in the tv.Bush themselves say we need a HD MI socket.Someone else tells us we need a download done on the tv.HELP which of these is correct and how do we get a download?