Television news is a medium dominated by producers, so, you need to 'produce' your interview, and not just show up at it. Know that you will be judged by your appearance Television is filled with people are paid to make snap judgments based on how things look, so they can't help themselves when it comes to you. Like it or not, you need to look as good as you can. Ladies, dress for success.
Pants suits seem to do the trick.
Guys, strap on a suit. Don't overdo it, though. Cake on too much make-up or hair gel and some techie might mistake you for the talent and throw you on the set. Either that, or the whole newsroom will laugh at you when you leave. Hopefully, a little of both.