I read a book a few weeks ago and the first sentence was No one knows what color the dinosaurs were... this made me think about it and I just wanted to know if this is true. While I was looking online and in all of my books about the dinosaurs, none of them said for sure what color they were. My friend and I have wanted to be paleontologists since first grade when she told me what it meant. So for about eight years I've been learning about them and this topic has never been there. I asked my friend what color she thought they were and she said green-gray like other reptiles, I told her that the reason she was able to answer me was because I asked her opinion on their color but if I had asked her what color they really were, she wouldn't be able to answer. Is this true or did I just not find the information that I was looking for?

We don't know what colors they were. Just as today's reptiles and amphibians come in all colors and combinations of colors, it was probably so with dinosaurs. Their coloration may have depended on where they lived, what they ate, mating requirements, and what defenses they needed.

What Color Were the Dinosaurs? | Scholastic.com

http://www.nytimes.com/2010/01/28/science/28dino.html

Scientists are not sure whether dinosaurs were warm blooded or cold blooded. If cold blooded then they were reptiles, warm blooded then they were not. But scientists say that actually some may have been either. And also that they may have been feathered with bright colors.

Were Dinosaurs Really Reptiles? | Big Site of Amazing Facts ©

Stringer

It's pretty clear that dinosaurs were not reptiles, but more closely related to modern birds. Like birds, they were warm-blooded even though they laid eggs. As to skin color - there is no way to be sure about that, but I would bet that there were many different colors of dinosaurs, just as there are many different colors of animals today. But it would seem logical that most would have been rather drab gray or brown, as that is usually the best for camoflauge - which is important regardless of whether you are a hunter (think of the colors of lions or wolves for example) or prey (gazelles, squirrels, etc). Of course there are exceptions - like the bright stripes on a tiger - so there were probably exceptions among the dinosaurs as well. But again: since no human has ever seen a dinosaur except as a collection of long dead bones, no one truly knows.