It could also be brown, grey, black, or white with highlights of yellow, red, orange, green, blue, etc. (especially on its fins, tail, or head). Those could all be realistic. The fact is we just don't know that much with any certainty about what exact colors a wide variety of dinosaurs that lived more than 66 million years ago had. Modern animals aren't necessarily the best analogy either, since dinosaurs were very different types of ancient animals.
By the way, really cool models! They're very well done!