So I'm DMing a very Dragon-Heavy campaign that my friend gave me, but I seem to have trouble roleplaying dragons. I don't want to stop the campaign and find a new one because I'm having difficulty getting into character, but at the same time I feel that the PC's are growing tired of every dragon acting like any other high-class or noble NPC. Are there any personality traits of dragon types that are listed? Are there any guides on roleplaying them that I can be directed to?

So far there are four dragons that I have to roleplay: a male Copper Dragon who is just finding out he has a half-dragon daughter, a female Red dragon and a female Silver dragon that are playing against each other in the Great Game (MMV), and a male Green dragon that is currently trying to overthrow the Red dragon as most powerful dragon in the region.

Any suggestions?