This is from the "Walking With Dinosaurs" site.
By studying what we know about each animal's particular eyesight, its habits and its habitat, and using modern animals in a similar environment, we can make informed guesses as to the coloration of extinct animals, even dinosaurs.link
The text in the link may not match word for word the 2 or 3 minute program segment but both are very clear that the color schemes used in the program are informed guesses.
There is a "DisoveryKids" program that condenses the much longer "Walking with Dinosaurs" programs into 30 minute, kid friendly presentations. Each "Walking with Dinosaurs" program could make about 5 or 6 or these shorter programs. Each shorter program also has only one or two "behind the scenes" segments explaining the evidence so maybe the one you saw didn't include the segment on color schemes.
An informative link. It just goes to show that learning is also active, not just a passive pursuit.
It could be any of those - but the good news is that they did make an effort to disclose that it was informed guess.