Despite the common belief that dinosaurs are comoflagy colours, i can inform you, after watching the dinosaur 3D film in the Science Museum, that the dinosaur looks in Jurassic Park are far from conclusive. Above is my guess. I read this following passage after making my guess, it bares a striking resemblance to my instinctual one...
'....but other paleontologists say the opposite is true — that dinosaurs' skin could have been shades of purple, orange, red, even yellow with pink and blue spots! Rich and varied colors, they argue, might have helped dinosaurs to recognize one another and attract mates.' (Adapted from Dinosaurs: The Very Latest Information and Hands-On Activities From the Museum of the Rockies, by Liza Charlesworth and Bonnie Sachatello-Sawyer. A Scholastic Professional Book.)