Overlord dragons are only loosely based on D&D. The well-known rivalries between chromatic and metallic doesn't really exist here. 
However, they are still haughty, greedy, scaly bastards that can cast spells and have breath weapons, so your mileage may vary.

Worth nothing:
The only fully-fledged Dragon hanging around Norden is Gungnir, the guardian of the Sea Elves's sacred island. There are some [s]thieving rascals[/s] lindwyrms elsewhere, but they can't really compare to a Dragon Lord.