Hi Shadows,
The colours are imagined but based on science as we know it. Creatures like the T Rex had huge ocular cavities and brain scans show the area of the brain that dealt with vision were quite complex. These guys had great stereoscopic vision. If you look at present day nature…birds through to reptiles there are plenty of examples that show bright colouration with the most random “blotches” of colour that simply serve to attract the eye of an observer to that feature. Birds especially demonstrate this feature when trying to attract a mate. Other creatures use it to demonstrate and emphasize the fact that they are dominant etc. Its a given now in scientific thinking that birds are basically dinosaurs and as dinosaurs were around for millions of years its pretty safe to assume that they developed ways to attract…threaten etc through visual displays.
The next model Im producing is a juvenile T Rex as evidence is stacking up to tell us that they lived in family groups. The most startling new thinking is that many juvenile dinosaurs may well have been feathered. basically a fibrous coat of simplistic feathers.
Back to the T Rex colouration. I havent finished painting the adult yet (By the way…its called Stan as its based on the fossil nicknamed Stan by the people who found it. There are many casts of the skeleton around the world and the one Im using is at the manchester university Museum in the UK) 
As always…thanks for your comments.
