I was a TV producer for 25 years and will join in by saying no white, no black and no small print. It's hard to light black, and the details will disappear on video. White will make the lens open up and videographers are always bothered by that. And small, high contrast print makes the camera go wonky.
I personally like it when talent wears bright colors as it draws the eye. But most of the talent I worked with was in a news/information/sports type show, not a scripted piece. However, I peeked at your blog and you are too stunning to fade into the background! I say stand out.
Another thought is a chambray shirt with a bright scarf. Although that may not work with the plaid skirt. I have several teacher friends and they don't dress as conservatively as the teachers did back in the day.
I just googled "fashion blog teacher" as a image search and was rewarded with some interesting images.
Something else that might work is to bring a couple of different choices for the top and ask the producer's opinion.