That's a really intriguing question right there, and I can't wait to see which smartarse
with nothing better to do comments first.
Guess it's me then.
I volunteer that what you are seeing is standard def material , say ITV 4 via Freeview, and
a blue outline accompanies every item on the screen. In the photographic world this is known
as colour fringeing, and is a consequence of mediocre glass and/or poor lens design . You'd
think that TV cameras would be of a higher standard than this, but they often aren't .
And therefore there's nothing you can do about it.